Twitter today Monday April 13th announced that they have suspended the accounts of about 10,000 users using their accounts to tweet violent threats. Many of the users are suspected to be sympathizers of ISIS. Some of them are even using their accounts to recruit.
This is by far the biggest anti-ISIS action by Twitter. And it's coming after the social networking site was heavily criticized for allowing the Islamic State to use their platform in spreading ISIS propaganda. A few months ago, Twitter suspended about 2,000 accounts.