A group of ISIS supporters who call themselves the “Sons of Caliphate Army” have issued threats against Facebook founder Mark Zuckerberg and Twitter founder Jack Dorsey in a video released on Wednesday night, according to Vocativ.

In the video, called “Flames of the Supporters,” an image of Zuckerberg and Dorsey are depicted with bullet-holes on a backdrop of flames.

The video was discovered by Vocativ on the social-media platform Telegram and authenticated by Storyful. According to Quartz, the video was authenticated based on where it was initially hosted and the pattern in which is was first shared on social media.

In the video, the group vows to retaliate against the social media billionaires after their platforms took down or banned terrorism-related accounts:

“To Mark and Jack, founders of Twitter and Facebook and to their Crusader government

You announce daily that you suspended many of our accounts

And to you we say:

Is that all you can do?

You are not in our league. If you close one account, we will take 10 in return and soon your names will be erased after we delete you sites, Allah willing, and will know that we say is true.”

The video also depicts terrorist members hard at work hacking Facebook accounts, changing profile pictures and posting propaganda. The group claims ISIS has hacked more than 10,000 Facebook accounts and 5,000 Twitter accounts.

Facebook and Twitter told Quartz they would not be commenting on the video.