Twitter CEO Dick Costolo revealed that the Jihadist terror group ISIS (Islamic State) had threatened his life, in addition to the lives of his employees, during Vanity Fair‘s 20th New Establishment Summit in San Francisco this past week.

“Obviously that’s a jarring thing for anyone to deal with,” Costolo said, according to the Daily Mail. “After we started suspending their accounts, some folks affiliated with the organization used Twitter to declare that employees of Twitter and their management should be assassinated,”

Just last month, ISIS terrorists had taken to the social media platform in an attempt to recruit lone wolves operating in America and Europe to assassinate Twitter employees because the company had begun deleting ISIS accounts. Costolo revealed during the summit that was targeted as well. 

Twitter has several offices located throughout the world, with 12 in the United States–including their headquarters in San Francisco–and five in Europe. Additionally, the company has two locations in Latin America, three in Asia, two in Canada, and one in Australia. 

The social media giant’s platform has played a central role in ISIS’s attempts to spread their terrorist propaganda across the globe. In August of this year, ISIS even hijacked the #napaquake and #napaearthquake hashtags on Twitter to propel its warped interpretation of Sharia law.

Costolo has been treading a fine line between upholding the Constitution’s freedom of speech premise, while employing Twitter’s own terms of service and security tactics in what has become a global effort (both through munitions as well as over the Internet) to thwart the onslaught of terror being wrought by ISIS.

He highlighted that while having “‘a global public information-sharing channel” will give way to “people that use it for good,” noting that Twitter has been a tool for “beneficial social change in a number of countries around the world,” Twitter prohibits the use of their platform to promote evil and agendas that threaten to harm the safety and security of citizens both domestically as well as internationally. 

“It’s against our terms of service….It’s against the law in many of the countries in which we operate for them [ISIS] to use it to promote their organization. And when we do find those accounts we shut them down. We shut them down quite actively,” Costolo said, according to the Daily Mail.

In an interview with several members of Twitter’s staff in San Francisco last month, it was revealed to Breitbart News that Twitter has heightened its security recently, perhaps in an effort to secure itself from threats by ISIS.

Follow Adelle Nazarian on Twitter: @AdelleNaz