Whatever you call them, ISIS, Islamic State, Daesh, it’s hard to deny that they’ve become masters of online recruitment and propaganda. And that’s exactly what the hacktivist group known as “Anonymous” is determined to end. 

Anonymous claims to have taken down more than 20-thousand Twitter accounts of ISIS supporters. But other say it’s not that simple.

A former Anonymous member,  Gregg Housh ( @GreggHoush) explains.