Verizon blocks 4chan websites for sending DoS attacks

Earlier this week Verizon Wireless temporarily blocked traffic from some Web sites affiliated with the 4chan online forum on the grounds that some affiliate sites were apparently launching network attacks.

"Our network security system found traffic from some 4Chan Web sites that had strong potential to disrupt the Verizon Wireless network, affecting our customers' use of their services," Verizon spokesman Jeffrey Nelson wrote in an e-mail to CNET. "With continuing investigation, and ensuring no current risk of harm, we are giving the green-light to all 4Chan traffic. We will continue to monitor for any possibility of network harm."

The company did not elaborate on which sites exactly were affected and what the trouble was. According to 4chan status page the sites appear to have been "explicitly blocked" for as long as three days.

In July, AT&T blocked a 4chan server after another site launched a denial-of-service type of attack called a SYN Flood attack on the site.

In its company blog Verizon later published the following:

"Recently, Verizon Wireless security and external experts detected attacks from an IP address associated with the 4Chan family of web sites that was disruptive to our customers and our network. To protect both, we eliminated connectivity to the IP address. At no time was 4Chan itself blocked. Ongoing network security team monitoring has now determined there is no longer an immediate threat. Connectivity to those sites is being restored later today.

"Typically, these attacks involve someone sending hundreds of thousands of messages to wireless devices to round up active customer addresses for follow-up activity including hacker attacks. These 'sweeps' can jam our network and deliver unwanted electronic messages that also can drain customer devices' battery life and slow their operation.

"We take being the nation's most reliable wireless network seriously. Seriously enough to protect our customers and our network from malicious attacks, even if we get dinged in the blogosphere. It's easy to complain about 'blocking' when your wireless data connection is stable, fast and reliable. But try connecting to the web from your Droid or Blackberry when attacks slow - and potentially block - use of our network all together.

"We monitor against attacks and potential attacks to ensure the integrity of the Verizon Wireless network. Our customers expect nothing less."