'Anonymous' declares 'war' on ISIS
'Anonymous' declares 'war' on ISISScreenshot

Hacker group Anonymous's "war" on Islamic State (ISIS) began last week - and the group has chosen to invoke a sense of humor. 

Anonymous hacked several ISIS Twitter accounts as part of its campaign, infiltrating the group's #SupportISIS propaganda campaign by posting links disguised as Islamist - but which really link to UK singer Rick Astley's "Never Gonna Give You Up" video from 1987.

The trick, known colloquially as a "Rickroll," reignited Astley's career in the late 2000s, after the prank became an internet staple.

"Rickrolls" have become a classic time-wasting prank for internet users, with the joke playing as well on various aspects of the video itself: its blatant eighties' character, Astley's obvious youth, and parts which look overwhelmingly lip-synced. 

Anonymous announced Wednesday that "Rickrolls" would be a strategic part of its campaign against ISIS, hoping users looking for jihadist material give up amidst a deluge of 1980s music videos.