Twitter’s terms of service explicitly ban “direct, specific threats of violence against others”, and the company has followed YouTube in proactively shutting down ISIS-related Twitter accounts
ISIS has been under attack in the last few days from Twitter, which has quietly suspended at least 2,000 accounts linked to the terror group and its supporters, according to people with knowledge of the operation.
The sites shut down include some of the most important distributors of ISIS messages in a major escalation against ISIS’s propaganda and recruitment efforts, according to J.M. Berger, a terrorism analyst who monitors ISIS online messaging.
"Twitter has been doing a whole lot over the past week. They've slammed them pretty hard, including the official media distribution guys," Berger said. He said 13 of the 16 major ISIS distribution accounts were among those shut down.
Top U.S. security officials previously said ISIS has successfully leveraged social media networks, including Twitter, as powerful recruitment tools to draw in fighters from 90 countries. But a person with knowledge of Twitter’s recent suspension spree said it was not done due to U.S. government pressure -– in fact, he said the U.S. intelligence community would prefer the accounts stay open for intelligence gathering purposes.