The founders and chief executives of Facebook and Twitter have been threatened by a group with ties to the militant Islamists that calls themselves Islamic State (ISIS).
Posting a 25-minute roughly put-together video on social media site Telegram, a group calling itself the "sons of the Caliphate army" vows to retaliate against attempts by the social media companies to close accounts belonging to supporters of ISIS.
The video was discovered by analysts at media and tech company Vocativ in the deep web – the part of the internet not accessible via standard search engines -- and shows images of Facebook CEO Mark Zuckerberg and Jack Dorsey, the head of Twitter, covered with bullet holes at one point.
"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?," the message on the video states, according to Vocativ.
The video message goes on to threaten Zuckerberg and Dorsey stating: "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 (sic) sites, Allah willing."
ISIS is well-known for its sophisticated use of social media to disseminate its ideology, making it a key target for authorities looking to combat the group and its influence. In the video, the hackers claim they control more than 10,000 Facebook accounts, 150 Facebook groups and 5,000 Twitter profiles.
Earlier this month Twitter said in a blog that it had suspended 125,000 accounts "for threatening or promoting terrorist acts, primarily related to ISIS." Likewise, Vocativ noted that Facebook has said that it works to ensure that terrorists don't use the site and removes content supporting terrorism.
Commenting on the video, Twitter told The Guardian newspaper on Wednesday that threats against Dorsey were now so common they wouldn't be releasing any official response. "It just happens all the time," a spokesman said, the paper reported. Facebook has not commented on the video.