Members of the hacking group “Anonymous” claim to be virtually terrorizing members of the Islamic State, hacking their social media accounts, crashing their websites, and dumping their personal information online.

On Twitter, a variety of accounts affiliated with the group claim to have made progress in that campaign. One account, called “#OpParis,” claimed Tuesday to have taken down thousands of Twitter accounts belonging to ISIS. “We report that more than 5,500 Twitter account of #ISIS are now down!” the account tweeted.