AT&T Blocking Part of 4chan, Then Restores Access (Updated)
posted on by Christopher Macdonald
According to a status update by 4chan maintainer moot, AT&T is blocking its customers from accessing parts of the 4chan message boards, including /b/ ("random"), which is responsible for 30% of 4chan's traffic.
4chan's /b/ section is infamous for its "no rules" policy, with the only rules being a ban on certain illegal content, such as child-pornography (although virtual child-pornography is tolerated), and "invasions" (organized incursions into and flooding of other online communities).
AT&T has made no statement explaining or even confirming the action.
Originally an English spin off of the Japanese 2chan BBS, 4chan has become immensely popular in its own right.
Update: Shon Elliott, a senior network engineer at another Internet service provider named unWired Broadband, reports that his company also blocked 4chan because of a deluge of network traffic from the server. The deluge of unnecessary ACK scan reports is one kind of denial of service (DoS) attack, which floods a network device with so much traffic that other computers or device might be unable to reach it for legitimate network traffic.
According to the TechCrunch website, AT&T confirmed its temporary block of 4chan when it restored access by Monday morning ET. AT&T emphasized that the reason for the block was a DoS attack, and "was in no way related to the content at img.4chan.org."
this article has been modified since it was originally posted; see change history