UK users of the popular Fileserve file-hosting service are currently unable to download any files as the site is being blocked by the Internet Watch Foundation. Since early this week the blacklist, which aims to disable access to sexual child abuse content, has been preventing users from accessing their personal files and downloading those uploaded by others. Fileserve expects the issue to persist for at least a couple of days.

With hundreds of millions of page views each month, Fileserve is listed among the 10 most-visited file-sharing sites on the Internet. The site allows users to store files in the cloud for personal use or subsequent sharing with the rest of the world.

For the past several days, however, many Fileserve users from the UK have noticed they are unable to download files to their computers using the service.

Initially, users got a standard error message that the download could not be completed, but yesterday users got an updated message telling them that their downloads are being blocked by the Internet Watch Foundation (IWF).

Internet Watch Foundation is a self-regulatory body that maintains a list of URLs that point to sexual child abuse and criminally obscene adult content. This list is used by all major UK Internet providers to prevent their subscribers from accessing these files. Unfortunately, however, the blacklist sometimes takes out legitimate services as well.

Fileserve users who try to download a file now see the following message which suggests that upgrading to a premium account will solve the problem, but TorrentFreak has learned that this is not the case. Premium users are also blocked.

Commenting on the issue, Fileserve confirms that a recent addition to the IWF blacklist is indeed causing problems for UK users. Although Fileserve expects that it will be eventually resolved, the file-hoster doesn’t think this will happen on short notice.

“Once again IWF has put Fileserve into watch list until further investigation from their side is done. It is not expected to be lifted within the next few days. IWF for UK is being very thorough in filtering Fileserve users,” the file-hoster informed one of their users.

“Please be reminded that it is not our will to have our UK users suffer from this, our Tech team are now looking into possible solution in getting around this IWF issue,” they added.

At this point little is known about the origin of the problem. It is clear that IWF has started to block one or more Fileserve URLs, but why all downloads are affected remains unknown. This is not the first time that the IWF blacklist has rendered legitimate content unavailable though.

In 2008 the blacklist censored the Wikipedia entry for the album “The Virgin Killer” from the German band Scorpions. This page was reported to IWF by a member of the public, and only after Wikipedia appealed twice did the IWF board decide to take it off the list.

Early January 2009 Archive.org’s Wayback Machine was entirely blocked by a UK ISP because one of the pages was listed on the IWF blacklist. This time the problem was due to conflicting incoming headers at Archive.org, beyond the control of IWF or the ISP.

The above suggests that Fileserve’s problems don’t necessarily have to result from a reconfigured blacklist.

In a week where Internet Censorship is a hot topic, the above is yet another reason why baking censorship tools into law has to be done wisely. In the case of Fileserve the IWF blacklist has rendered their site completely unusable to hundreds of thousands of UK users, something that may cost them if the problem persists.

TorrentFreak contacted the Internet Watch Foundation for a comment, and we will update this article when a response comes in.

Update: IWF confirmed to TorrentFreak that they added a single URL of Fileserve to their list, not the entire domain.

“We received a report of child sexual abuse content hosted on a Fileserve URL which was assessed as criminal under UK law. It is not uncommon to see child sexual abuse content hosted on legitimate cloud storage sites, in our most recent Annual Report we identified this trend as increasing. Our members Virgin Media have been investigating an issue regarding a Fileserve splash page message, the IWF have no control over any of the messages provided by Fileserve,” we were told.