"As horrific as these deaths were," he wrote, "Twitter cannot be treated as a publisher or speaker of Isis' hateful rhetoric and is not liable under the facts alleged." He explained that under the Communications Decency Act, online content providers like social networks cannot be held liable for tweets, status updates or anything else published by a third party.

While there's undoubtedly quite a lot of Twitter accounts disseminating pro-ISIS propaganda, the company has been trying to fight them off. An intelligence report said it routinely deletes accounts related to the terrorist organization faster than ISIS can make them. The White House is also a fan, announcing that the group's Twitter activity dropped 45 percent in the past two years.