Anonymous links are being used to launch  DDoS attack on US Government, according to insecurity outfit Sophos. The latest Anonymous attack, dubbed #OpMegaupload is being carried out simply clicking on Anonymous links, which are being spread on Twitter.

If you click on them  users will instantly launch a denial-of-service attack which will begin to flood a website of Anonymous's choice with unwanted traffic. Anonymous has claimed that it's attacking numerous websites in this way, including those belonging to the FBI, Department of Justice, RIAA, MPAA and Universal: "We Anonymous are launching our largest attack ever on government and music industry sites. Lulz. The FBI didn't think they would get away with this did they? They should have expected us."

These attacks follow on from this week's internet blackout, where thousands of sites participated in protest against proposed US anti-piracy legislation. Further to this, file-sharing website Megaupload was shut down yesterday, and its founders arrested.

Graham Cluley, senior technology consultant at Sophos said in the past, Anonymous has encouraged supporters to install a program called LOIC, which allows computers to join in an attack on a particular website, blasting it with unwanted traffic.

"This change in tactic from Anonymous, which allows attacks to be launched by simply clicking on a link, means that internet users need to be extremely careful when clicking on unknown URLs or they could unwittingly be joining this latest zombie army."

Cluley warned that Denial-of-service-attacks were illegal and participation could result in a jail sentence. He did not think any US court would buy participants saying that they innocently clicked on links by mistake.