ISPA seeks analysis of BT's 'Cleanfeed' stats

ISPA - the trade group for the UK's ISPs - wants to carry out an analysis of BT's "Cleanfeed" Web filtering system because of concerns that the data might be giving a misleading picture of the scale of Internet child abuse.

Yesterday, BT said that in the last three weeks it had blocked 230,000 attempts to access child abuse websites. The announcement caused a flurry of media attention raising fears that thousands of people in the UK are trying to access illegal child abuse websites.

While ISPA said it "welcomes any developments in the fight against child abuse images appearing on the Internet", it is concerned that the stats could be misleading. It wants to conduct an analysis of the statistics so that it can give "appropriately informed comment on the system and the data that has been published".

"Only then will we be in a position to ascertain if and how many people are actually trying to access these websites, and hence understand the true scale of the problem," it said in a statement.

BT has seen the ISPA statement and has promised to respond in due course.

ISPA's Statement In Full

ISPA welcomes new developments in the fight against child abuse images appearing on the Internet. However ISPA feels caution is needed with the information and statistics so far available on Cleanfeed.

It is very difficult to comment on the statistics reported by BT regarding Cleanfeed as BT has not passed the data to ISPA.

At present there seems to be a significant disparity in the statistics that are being reported.

20,000 URL requests per day reported by [BT Retail chief exec] Pierre Danon on Tuesday morning on BBC Radio 4 does not equate to 230,000 URL requests per day between June 21st and July 13th, which would mean around 10,000 URL requests per day.

There is also a need to understand exactly what Cleanfeed is detecting.

At present we do not know if Cleanfeed is measuring the number of 'hits' (attempts to download individual files from illegal websites) or 'visits' (number of attempts to visit the website).

Also, if the Cleanfeed uses URLs of specific images, then that is likely to have an impact on the statistics. If the database contains URLs of images rather than the pages holding them, one page would cause several 'hits'.

Since Cleanfeed gives a "not found" error, people visiting the sites are going to assume that it was an error and probably retry at least once. That could potentially increase the statistics by a factor of at least 2. It would be better if Cleanfeed stated that the website is blocked and cannot be accessed.

Cleanfeed could also be detecting URL requests generated by a variety of other methods which would potentially inflate the figures reported. For example people may be mistakenly clicking on URLs whilst looking for legitimate websites, webcrawlers could be requesting the URLs, requests to access URLs could be generated by pop-ups and there are a number of other automated processes that could cause URL requests.

ISPA would like to conduct an analysis of the statistics to give appropriately informed comment on the system and the data that has been published. Only then will we be in a position to ascertain if and how many people are actually trying to access these websites, and hence understand the true scale of the problem.

Application of Cleanfeed to other ISPs

Each ISP has a different infrastructure. This means that there is no 'one size fits' all technical solution to preventing access to web sites offering illegal images in territories outside of the UK.

As with any technical solution, care must be taken to ensure blocking web sites offering illegal images does not cause unacceptable levels of collateral damage. Any such technical measures must be evaluated by ISPs over time to judge their success.

The Cleanfeed solution now under trial by BT will only prevent "casual" browsing of known web sites. It will not hinder organised distribution of such images. It will not prevent access to new web sites offering illegal content, nor will it prevent children being abused.

The very presence of images of child abuse on the Internet is a problem. Preventing access is not a solution to the presence of these websites.

UK ISPs are successfully taking responsibility for removing illegal content hosted on their system once they have 'actual knowledge' that the materials are illegal. The UK Internet industry has been running a self-regulatory 'notice and takedown' procedure for criminal content for years. The success of this scheme is borne out by statistics released by the Internet Watch Foundation (IWF) in 2004.

In 2003 less than one per cent of illegal images reported to the IWF were hosted on the UK Internet.

The majority of illegal content on the Internet originates from the US and Eastern Europe. The Internet industries, law enforcement agencies and Governments in these territories should take action similar to the UK to limit access to illegal content. ®

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