Customers of AT&T DSL and U-Verse internet services throughout the United States began to notice Sunday evening that they were cut off from parts of the popular website 4chan.org. In particular, the /r9k/ and the infamous /b/ image boards could not be accessed.
The regions affected were largely in the West, Midwest, parts of Connecticut and Texas. No reports of blockage were reported in other parts of the United States.
AT&T later confirmed to CentralGadget.com that they were blocking portions of the site but did not disclose why they were doing it. Full access to the site was restored at around 1:50AM Eastern Monday morning.
As the news of this event bounced back and forth across the unblocked parts of 4chan, Twitter, IRC chat channels, message boards, blogs and at least three different wiki sites, a clear consensus emerged regarding what AT&T’s reasons might have been for blocking 4chan: censorship.
Several different image boards are hosted at the 4chan.org domain, each with its own theme. Due to their popularity and very heavy usage, the /r9k/ (Robot9000) and /b/ (Random) boards are hosted on their own separate web server.
/b/ is easily one of the most infamous destinations on the world wide web. Graphic, pornographic and highly offensive images are posted to the board on a regular basis. Comments from regular /b/ users – who refer to themselves proudly as /b/tards – are nearly always just as offensive as the images. It is not the sort of site you would want to be caught browsing while at work.
In other words, it is exactly the sort of thing that a censor would want to block.
AT&T’s blockage of 4chan on Sunday was targeted specifically at the web server which hosts /b/ and /r9k/. The rest of the domain was entirely unaffected. This seemed to many to be proof that AT&T was censoring customers’ internet access.
It is not the first time that AT&T has been accused of censorship. In 2007, AT&T tampered with the audio stream of a Pearl Jam concert, which was webcast over AT&T’s network. During the performance and without the permission of the band, AT&T edited from the stream lyrics which were critical of then President George Bush.
There is another possibility however. For the last several weeks, that same web server has been the target of a distributed denial of service attack (DDoS). One member of an email mailing list suggested that spoofed network packets might be bouncing from 4chan onto AT&T’s network.
It might not have been censorship after all. AT&T might simply have been trying to stop the bounced packets from disrupting their own network.
Since AT&T has failed to disclose exactly what it was they were doing, there is no way to know at this point what their motive may have been. AT&T may release some sort of press announcement later today, as this story already is all over the blogosphere and likely will be picked up by the mainstream press.
Whatever it was they were doing, AT&T seems to have stopped blocking the site. Users who had been blocked earlier began to report at around 1:50AM Eastern time that they could reach the site again.
Of course the entire 4chan site still is under assault from an ongoing denial of service attack. While the site is available, it is loading very slowly.
Dallas, Texas, July 27, 2009
Beginning Friday, an AT&T customer was impacted by a denial-of-service attack stemming from IP addresses connected to img.4chan.org. To prevent this attack from disrupting service for the impacted AT&T customer, and to prevent the attack from spreading to impact our other customers, AT&T temporarily blocked access to the IP addresses in question for our customers. This action was in no way related to the content at img.4chan.org; our focus was on protecting our customers from malicious traffic.
Overnight Sunday, after we determined the denial-of-service threat no longer existed, AT&T removed the block on the IP addresses in question. We will continue to monitor for denial-of-service activity and any malicious traffic to protect our customers.
For the past three weeks, 4chan has been under a constant DDoS attack. We were able to filter this specific type of attack in a fashion that was more or less transparent to the end user.
Unfortunately, as an unintended consequence of the method used, some Internet users received errant traffic from one of our network switches. A handful happened to be AT&T customers.
In response, AT&T filtered all traffic to and from our img.4chan.org IPs (which serve /b/ & /r9k/) for their entire network, instead of only the affected customers. AT&T did not contact us prior to implementing the block. Here is their statement regarding the matter.
In the end, this wasn’t a sinister act of censorship, but rather a bit of a mistake and a poorly executed, disproportionate response on AT&T’s part. Whoever pulled the trigger on blackholing the site probably didn’t anticipate [nor intend] the consequences of doing so.
We’re glad to see this short-lived debacle has prompted renewed interest and debate over net neutrality and internet censorship—two very important issues that don’t get nearly enough attention—so perhaps this was all just a blessing in disguise.