Updated The attack on a second law firm with a history of involvement in copyright litigation has turned out to be something of a damp squib. Anonymous extended its fight against organisations supporting anti-piracy efforts to solicitors Davenport Lyons on Thursday night, with plans to flood its website with spurious traffic and carry out a defacement.

The move is the latest phase in a campaign dubbed "Operation: Payback Is A Bitch", which began over the weekend with successful DDoS attacks against the websites of the Motion Picture Association of America and the Recording Industry Association of America (RIAA), before proceeding to less successful assault against the British Phonographic Industry (BPI). The campaign is a retaliation against the use by Bollywood studios of a firm called Aiplex Software, which launches DDoS attacks on Torrent sites that fail to respond to takedown notices. Aiplex was among the early targets of the attacks.

These assaults moved onto the website of solicitors ACS:Law on Tuesday, briefly taking it offline. The law firm sends threatening letters to alleged copyright infringers urging them to pay £500 or risk being taken to court.

The controversial tactic was originally carried out in 2007 by London-based law firm Davenport Lyons, which has since discontinued the practice, but its practice of sending nastygrams to alleged copyright offenders has earned the ire of Anonymous.

According to Panda Security, which has been tracking the progress of the attacks, Anonymous briefly succeeded in taking the Davenport Lyons website down late on Thursday night before a failed attempt to deface the site.

However, a spokeswoman for the solicitors told El Reg that "everything is normal here and it's all working fine". ®

Update

Sean-Paul Correll, a threat researcher at Panda Security told El Reg: "The Davenport Lyons IT team seems to have implemented some sort of DDoS protection. They've had three service interruptions and 8m 55s of total downtime."

The attack has since moved back onto Aiplex. And there's an alteration of the DDoS software, which allows users to act as a voluntary bot, Correll added.