Tag Archive for "filtering"

Sometimes it seems that every day there is another threat to people’s abilities to use the Internet. Each special interest group has their own barrow to push, often with honourable intent, that causes them to make impossible or unreasonable demands.

Today’s effort is from the Law Commission. They’ve published their Suppressing Names and Evidence report and it includes the following (recommendation 26 from the report, page 66, PDF):

Where an internet service provider or content host becomes aware that they are carrying or hosting information that they know is in breach of a suppression order, it should be an offence for them to fail to remove the information or to fail to block access to it as soon as reasonably practicable.

There’s nothing new in extending the current rules about not publishing suppressed material to hosting an Internet website publishing the suppressed material. Obviously someone will have to complain to the ISP (Internet Service Provider) that are hosting suppressed information, but the ISP will be able to refer to the judge’s suppression order and remove it. (Although of course there may be times when it is unclear whether a particular piece of information breaches a suppression order.)

The more worrying part is the use of the word “carrying” which, as far as I can tell, can only refer to information that the ISP is carrying between ‘somewhere on the Internet’ and the user.

By demanding that the ISP be able to block access to this information, the Law Commission is requiring all ISPs to implement a filtering system that is capable of blocking any access on any Internet protocol to any Internet address that may have the suppressed information. If they fail to do so, penalties include fines and imprisonment (exactly how you imprison an ISP I am not sure).

There are a number of problems with this:

  1. Each ISP would have to implement a filtering system (both technically and procedurally) and this would be very expensive.
  2. It puts an unreasonable responsibility on the ISP.
  3. Who would be responsible for removing information blocks when a suppression order is lifted?
  4. Most importantly, what they have asked for is technically impossible to implement.

Why is it technically impossible?

Information is shared on the Internet using a number of different methods (protocols). They include email, online chat, web pages, and peer to peer file-sharing. A number of these different protocols use encryption between the user and the site. For example, banks and online shops all use secure web traffic (HTTPS) to keep your transactions safe from interception.

If a piece of suppressed information is made available at an Internet address that uses encryption, the ISP can’t read the encrypted request and will therefore have to block all traffic to that Internet address. If your online shop uses the same Internet address as a site with suppressed information (sharing Internet addresses is very common, with some addresses hosting thousands of sites), access to your shop will also be blocked.

This means that every time someone overseas publishes information contrary to a suppression order from the New Zealand courts, a number of websites will have to be blocked. This will fundamentally break the Internet in New Zealand.

Of course, if you run a bookstore in New Zealand I suggest that you might find it advantageous to make sure to add some suppressed information to a review on amazon.com!

This doesn’t even cover the technical difficulties and costs involved in deploying a blocking system that can filter everything on the Internet. You may note that the Chinese Government has spent a lot of time and effort building their Great Firewall of China and even that does a poor job of blocking information.

Conclusion

I believe the Law Commission needs to rethink this recommendation. The blocking they have asked for is technically impossible to implement without breaking the Internet.

Of course, if it’s impossible to suppress information on the Internet, is there any point in suppressing it in newspapers and other media? We may have to accept that we cannot suppress information on a pervasive global communications network.

It looks as though the Law Commission’s report may be obsolete on the day it was published.

Update on Filtering

Today I met with some of the staff in the Censorship Unit at the Department of Internal Affairs to discuss the Internet filtering system.

Here’s some of what I learnt:

  • The Censorship Unit prosecute approximately 40-50 people a year for trading in child pornography, with a conviction rate of over 90%. Most of these are using P2P file sharing.
  • The purpose of the filter is not to stop the hard core traders, but to stop the casual and curious. The view is that a curious person will be sucked into getting more and more.
  • The Enterprise (final live system) Internet filtering system will be installed in Auckland, Wellington and Christchurch. Initially all traffic will go through the Auckland location with the others as redundant fail-over sites, eventually the traffic will be load-balanced between the sites.
  • The system also has redundant Internet connections.
  • The DIA claims that a major outage would be resolved in 5-10 minutes at worst.
  • The DIA say that the cost of the system is approximately $30k a year plus Internet and staff costs.
  • They really do re-check 7000 sites each month. Apparently there are three checkers who spend about an hour each working day, checking about 120 sites each an hour.
  • The Code of Practice is being rewritten somewhat in response to the submissions. In particular, the role of the Independent Reference Group (IRG) will be better defined.
  • The IRG will have access to the reports about the websites as well as the details of the appeal.
  • The DIA have been speaking to likely bodies to see if they wish to be part of the IRG.
  • There may be a role for the Office of Film and Literature Classification in auditing the list of banned sites.
  • We confirmed that the system doesn’t work with HTTPS (encrypted web traffic) and the new IP version 6.
  • The NetClean (the filtering product being used) contract specifies that the system can only be used to filter child pornography.
  • They say that they wouldn’t add Wikileaks to the filter if a copy of the list turned up there.

I will be updating the FAQs accordingly.

No! But yes.

I have received another letter from the DIA (PDF) in response to further requests.

As well as a copy of the whitepaper that I’ve already written about, I asked the DIA to clarify “whether the filter will only be used for images of child sexual abuse or will it also be used for text files as described by Trevor Henry, Senior Communications Advisor on 17/7/2009”.

The response from Steve O’Brien, manager of the Censorship Compliance Unit, was as follows:

Unfortunately, Trevor Henry’s statement has been taken by some commentators as “proof” that the scope of the Digital Child Exploitation Filtering System will expand. As stated above, the purpose of the filtering system is to block access to known websites that contain images of child sexual abuse.

Well, I’m glad we cleared that up, the filter is only going to be used for pictures. But wait, what’s this, he hasn’t finished yet:

These websites sometimes also contain text files that exploit children for sexual purposes, and where this occurs those text files will also be blocked.

The concept of a text file exploiting a child seems odd to me.

Even ignoring the slightly ludicrous phrasing, part of the rhetoric around the implementation of the filter has been that they are trying to stop photos of actual abuse – “…will focus solely on websites offering clearly objectionable images of child sexual abuse.” There is no child being abused in a text file.

The examples given by Trevor Henry clearly demonstrate that written material can be just as abusive as pictures.

I don’t believe that he did clearly demonstrate that (read what he wrote). While what he describes is creepy, to my mind there is a clear distinction between writing about how to abuse a child and actually abusing one.

So, has this response cleared anything up? The answer has to be no. The DIA is still claiming that it’s trying to only ban images of child sexual abuse (something I might be inclined to support if they did it openly and if it had any chance of working) while at the same time admitting that they’ll ban other things that aren’t images as well.

DIA Report on Internet Filter Test

The Department of Internal Affairs (DIA) have released to me their report (PDF) on the testing of the Internet Filtering system.

The first half of it is a description of the system and doesn’t really contain much new information (except that we now know it runs on FreeBSD and uses the Quagga BGP daemon).

The second half of it is more interesting as it has some results from the DIA’s testing. This was apparently split into three phases:

  1. Single ISP with 5,000 users ((already had their own filtering system so it was probably Watchdog).
  2. Two ISPs with 25,000 users.
  3. Four ISPs with 600,000 users (at a guess this was when Ihug and TelstraClear joined).

Before we go on, a brief reminder of how it works: The ISP diverts all requests that are on the same Internet address as one of the blocked sites. The filter then checks each diverted request and decides whether to block it or let it through. The filter never sees requests for websites that don’t share an Internet address with a blocked site.

Interceptions

Now, back to the numbers. The phrasing in the whitepaper is a bit hard to interpret, the following is based on my best attempt at understanding it:

In phase 1, the system apparently had 3 million requests diverted to it each month and blocked 10,000 of those requests. This means that only a third of 1% of processed requests ended up being blocked.

In phase 2, there’s 8 million requests per month with 30,000 of them being blocked.

In phase 3, there’s 40 million requests per month with 100,000 of them being blocked.

In other words, there’s a very large number of requests being filtered through the DIA’s server compared to the number that are being blocked.

Effectiveness

There’s no way to measure the effectiveness of the filter at stopping people from finding child pornography – we can’t tell how many people worked around it or downloaded material using peer to peer filesharing or other methods.

One interesting number, however, is the number of blocked requests per user.

In phase 1, there’s 2 blocked requests per user per month (10,000 blocked requests per month/5000 users).

In phase 2, there’s just over 1 blocked request per user per month (average 30,000 blocked requests per month, 25,000 users).

In phase 3, there’s 0.17 (average 100,000 blocked requests per month, 600,000 users).

What’s odd is the way that the number of blocked requests per user go down phase by phase. I have no idea what this indicates.

Robustness

According to the report, the system was operating at 80% capacity in the third phase. Apparently this was a bit much for it as: “the system did experience some stability issues processing this amount of requests and required maintenance on two occasions to replace hardware.”

There is no further detail about whether the “80% capacity” referred to the performance of the filtering system or the Internet connection they were using.

Government Department Powers

I sent in a submission to the Department of Internal Affairs about the Internet filtering scheme. Originally I was intending to run the normal arguments (which I’m sure anyone reading this is already familiar with) but I started to think about the constitutionality of the scheme – and my submission got away on me a bit.

Here’s some of the questions I’m thinking about:

  1. Where does the DIA derive the authority to create and implement the Internet filtering scheme from? I can’t find any basis for it in the 1993 Films, Videos and Publications Classification Act that they mention in the draft Code of Practice.
  2. Can Government departments just make new powers up? What avenues are available to stop them?
  3. Even if there was some basis in the 1993 law, it’s very clear about censorship decisions having to be published, and also defines an accountable appeals process. The DIA seems to have completely ignored this when designing their scheme. Again, how can they do this and how can we stop them?
  4. When a new law is proposed that has Bill of Rights implications (“Everyone has the right to be secure against unreasonable search or seizure, whether of the person, property, or correspondence or otherwise” seems relevant), the Attorney-General has to submit a report to Parliament on those implications. Is there anything similar when Government departments create new powers for themselves? How does the Bill of Rights work if government departments can just ignore it?

If anyone has any answers to these questions or can point me in the direction of a constitutional lawyer who wouldn’t mind giving some free advice for a good cause, I’d be very grateful.

Why Even an Ineffectual Filter is Worrying

A friend recently said that he thought he’d found a flaw in my arguments. Firstly I was saying that the DIA’s Internet filtering scheme won’t really work, and secondly I was saying that it was the first step on the slippery slope of out of control Internet censorship. How can the filtering scheme be a threat if it doesn’t even work?

There are two answers to this.

1. Does the Filter Work?

The Internet filtering scheme proposed by the Department of Internal Affairs is good at some things and bad at others.

What It’s Good At

The Netclean filter used by the DIA is limited to stopping access to particular websites or parts of websites based on their Internet address and path. This means that it’s good at stopping casual access to a known web-page that doesn’t get moved around.

If, for the sake of argument, the DIA decided to use the system to ban access to a certain page on Wikipedia, this would easily stop normal Internet users from accessing the page. They would try to visit the page, they’d get the page saying it had been banned – and they’d stop there because they probably don’t really care that much, nor do they know how to get around the filter.

What It’s Not so Good At

It’s not very good at stopping people who are deliberately trading illegal material. Firstly, they’re coordinating the trading by chat and then sharing the files using peer to peer (P2P) systems – both of which aren’t blocked by the DIA’s Internet filter. Secondly, the content keeps getting moved around in order to avoid being shut down. Thirdly, the people doing this know that what they’re doing is wrong and illegal, so they’re actively taking measures to protect themselves such as using encrypted proxies in other countries. The filter will hardly even slow them down.

The more conspiracy-minded among you might ask why the DIA are trying to implement a scheme that won’t do a very good job of achieving it’s stated purpose but could be used to block access for normal people to normal websites.

2. The Filtering Principle

The more important reason to my mind is the slippery slope argument. While the currently proposed Internet filtering scheme is more ineffectual than scary, a successful implementation will establish some important and far-reaching principles such as:

  1. The Department of Internal Affairs has the right to arbitrarily decide to filter the Internet.
  2. The DIA has the right to decide what material should be filtered.
  3. It is acceptable for the government to intercept and examine Internet traffic without a search warrant.
  4. When censoring Internet content there is no need to meet the same oversight requirements that apply when censoring books or movies.
  5. The ISPs will happily censor their users.

I don’t agree with these principles, and once they’re established in practice it will be significantly harder to argue against them in the future if things change. For example, if the DIA decided to change the methodology used for the filtering to a more invasive/disruptive one, or chose to drastically extend the scope of the material to be filtered.

Answer

So, to answer the original question, the DIA’s proposed Internet filter will be ineffectual at stopping the trade in child pornography, and it’s the implications of implementing it that particularly worry me.

Three News Items of Interest

UK’s Child Exploitation and Online Protection Centre

The UK’s Child Exploitation and Online Protection Centre (CEOP) has released its latest annual report (2008/2009). While they cover a much wider range of activity, one of the findings is highly relevant to the debate about Internet filtering in New Zealand.

Similarly we can report a step change in the way that offenders access images, with the vast majority of trading taking place on various peer to peer (P2P) platforms. Our focus must now be on tackling this as a priority.

What’s relevant about this? The Department of Internal Affairs’ proposed Internet filtering scheme only works with unencrypted websites, and is useless against P2P file trading.

How Voluntary Ends

The UK has a non-government voluntary web-filtering system that Internet Service Providers (ISPs) can sign up for. Well, as reported by the Independent, it won’t be voluntary very soon:

The leaked Home Office letter says a clause in the Police, Crime and Private Security Bill in the Queen’s Speech would “compel domestic ISPs to implement the blocking of illegal images of child sexual abuse”.

The New Zealand system is also voluntary for ISPs. I’m worried that the voluntary nature of the scheme will only last as long as it takes to get established.

Filtering Systems are an Opportunity for People Who Wish to Suppress Free Speech

Finally there’s an article about an attempt by Scientologists in Australia to not only have anti-Scientology sites added to the Australian Internet filter, but also sites that provide anonymisation services to those sites.

We have identified that such websites play a major role in the ongoing hate campaign against our Church and their removal or a restriction of access and of content would play a major role in preventing further religious vilification against us.

It is therefore recommended that the Australian Government take action to prevent to the creators of websites, whose primary purpose is the incitement of religious vilification, to be prevented from using programs such as WhoisGuard to conceal their identity, so that normal recourse to the law may be accessed as needed to defend basic rights covered by Australian law.

One of the problems with Internet filtering is that, once it’s established, there are no more technical and legal difficulties in banning material on the Internet. This means that the filter is now fair game to every group that has a bee in their bonnet about controlling access to certain sorts of information.

A Status Update

Well, my blog has well and truly been taken over by Internet filtering. Things have been a bit quiet recently, so here’s an update:

  • I’m still waiting for the Ombudsman’s report on whether I can have access to the list of filtered sites.
  • I haven’t heard from Archives about the DIA deleting their records.
  • I have been persuaded to spell Internet with a capital I even though I prefer to be a little more avant garde.
  • I’m part of the Internet NZ working group developing policy on Internet filtering.
  • I’m working on collecting more information (still no response from the Maori or Act parties, waiting to hear from ISPs, have more questions to send to the DIA and the Censor).

So, what’s next? I’m thinking a lot about how to continue the campaign against Internet filtering, while also considering some of the larger issues that this raises about protecting the civil liberties of Internet users. Email me if you’ve got any ideas or what to help.

IT Minister Steven Joyce has finally sent me a reply. This was in response to me asking him about his statements in NBR against the idea of Internet filtering:

We have been following the internet filtering debate in Australia but have no plans to introduce something similar here.

The technology for internet filtering causes delays for all internet users. And unfortunately those who are determined to get around any filter will find a way to do so. Our view is that educating kids and parents about being safe on the internet is the best way of tackling the problem.

I asked:

  • Are you still against the introduction of internet filtering?
  • Does the National government have a policy for or against internet filtering?

His letter didn’t answer either question, the only substantive part of it was:

I would like to say first off that the voluntary website filering system being proposed in New Zealand by the Department of Internal Affairs is significantly different in design and scope from the mandatory system proposed in Australia.

He then listed a number of differences in the systems and suggested I talk to the Department of Internal Affairs about it.

What I find interesting about this letter is that he carefully avoids answering both of the questions I asked. Steven Joyce refuses to say that he now supports Internet filtering, and also refuses to take the opportunity to state whether the National government has a policy for or against it.

I find this lack of clear political support for the scheme to be heartening.

DIA Admits Filter Shortcomings

Don’t just take my word for it, let’s see what the Department of Internal Affairs has to say about how well their system works (the following quoted text is all from the draft Code of Practice):

ISPs Might Not Participate

Participation in the Digital Child Exploitation Filtering System by ISPs is therefore voluntary and this provides an effective means of ensuring that the system keeps to its stated purpose. If ISPs become uncomfortable with the direction of the system, they can withdraw.

Doesn’t Prevent the Creation of Illegal Material and the Exploitation of Children

The Department of Internal Affairs appreciates that website filtering is only partially effective in combating the trade in child sexual abuse images. In particular website filtering is effective only after the fact and does not prevent the creation of illegal material nor, in the case of images of child sexual abuse, the exploitation of children.

Doesn’t Catch the People Doing It

The system also will not remove illegal content from its location on the Internet, nor prosecute the creators or intentional consumers of this material.

Can Easily be Circumvented

The Department also acknowledges that website filtering systems are not 100% effective in preventing access to illegal material. A person with a reasonable level of technical skill can use tools that are freely available on the Internet to get around the filters.

Doesn’t Stop File Sharing or Chatrooms

As illegal material, such as child sexual abuse images, is most often traded on peer-to-peer networks or chatrooms, which will not be filtered, the Censorship Compliance Unit carries out active investigations in those spaces.

Might Give Parents a False Sense of Security

The Department is aware that a website filter could give parents a false sense of security regarding their children’s online experience. Filters are unable to address all online risks, such as cyber-bullying, online sexual predators, viruses, or the theft of personal information.

Maybe the DIA should persuade themselves that Internet filtering is a good idea before trying to implement it.