AT&T blocked portions of the 4chan.org bulletin board July 25 and 26 in response to denial-of-service attacks against an AT&T customer, touching off a debate on censorship and network neutrality.
In response to criticism, AT&T stressed that it moved against 4chan.org because of the attack, and not because of content posted there.
"Beginning Friday [July 24], an AT&T customer was impacted by a denial-of-service attack stemming from IP addresses connected to img.4chan.org," AT&T officials said in a statement. "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."
AT&T said it lifted the block on the IP addresses in question overnight July 26 after the threat was over.
"We will continue to monitor for denial-of-service activity and any malicious traffic to protect our customers," the company said.
The move against 4chan.org set off a torrent of anger from users who felt AT&T was playing the role of digital censor. Launched in 2003, 4chan's message board has become notorious in some circles for its content, which users can post anonymously.
4Chan.org founder Christopher "Moot" Poole wrote July 26 that AT&T had not contacted him about its actions, and urged 4chan users to contact customer support and complain about the move. Some are speculating that some 4chan.org users may have taken it a step further, as not long after news of the block became public, a fake report about the death of AT&T CEO Randall Stephenson surfaced on CNN's iReport. The story has since been removed.
At least one other ISP-UnWired Broadband-joined AT&T in blocking portions of the site.
"There [have] been a lot of customers on our network who were complaining about ACK scan reports coming from 220.127.116.11," Shon Elliott, senior network engineer at UnWired, wrote on the NANOG (North American Network Operators Group) message board. "We had no choice but to block that single IP until the attacks let up."