SAN FRANCISCO - A video purportedly made by supporters of the Islamic State makes direct threats against Facebook CEO Mark Zuckerberg and Twitter CEO Jack Dorsey for combatting terrorism on their internet platforms.
The 25-minute propaganda video was released by a group calling itself "the sons of the Caliphate army". In it, photographs of both technology leaders are targeted by bullets. The video was spotted by Vocativ deep web analysts on the chat app Telegram, which is used by the Islamic State (IS) - also known as ISIS and ISIL.
The extremist group says it's responding to growing efforts by Facebook and Twitter to suspend accounts and remove posts that the social media services say incite violence and promote terrorism.
The video shows hackers changing profile accounts and posting IS propaganda. They allege they hacked more than 10,000 Facebook accounts, more than 150 Facebook groups and more than 5,000 Twitter profiles. "Many of these accounts have been given to supporters," the video says.
Twitter declined to comment. Facebook could not be reached for comment.
Internet companies are under growing pressure to more effectively police the presence of the extremist group in the wake of the terrorist attacks in Paris and in San Bernardino County.
The IS uses popular internet services such as Twitter and Facebook to spread propaganda, to attract and train new recruits and celebrate attacks.
"We don't want people doing that kind of stuff on Facebook," Mr Zuckerberg said on stage at Mobile World Congress held in Barcelona, Spain this week.
"If we have opportunities to basically work with governments and folks to make sure that there aren't terrorist attacks then we're going to take those opportunities and we feel a pretty strong responsibility to help make sure that society is safe," Mr Zuckerberg added.
Twitter said earlier this month that it suspended 125,000 accounts connected to the IS over the past six months. It was the first time Twitter shared specifics on the number of accounts it has deleted.
Twitter's strategy is working, according to a study from George Washington University.
But Veryan Khan, editorial director at the Terrorism Research and Analysis Consortium, a private firm that collects information on terrorism, says though Twitter may have made a dent, "the bounce back for the Islamic State will be fairly effortless".
"The Islamic State has been preparing their sympathisers for this type of event. Loads of Just Paste Its and Dump To bins as well as ‘how to' videos have been circulating over this month on how to create dozens of backup accounts easily including creating false working phone numbers for those using Tor," she said.
Sons of the Caliphate is a small offshoot of the Cyber Caliphate that analysts speculate is a "teen" or "apprentice" division.
Ms Khan says this is the first time an IS-linked group has made a threat - at least publicly - against Mr Zuckerberg. But these groups have made similar threats against Twitter in the past.
After Twitter began cracking down on terrorists in 2014, it received death threats, the company's then CEO told Vanity Fair at the time.
Dick Costolo, former Twitter CEO, said IS fighters threatened to "assassinate" him and other Twitter employees.
"That's a jarring thing for anyone to deal with," he said.
In March 2015, the IS threatened Mr Dorsey, Twitter's co-founder and chairman, and all Twitter employees for shutting down accounts. The group claimed that Mr Dorsey and Twitter had started a "war" with the IS and Twitter employees had "become an official target to ISIS soldiers and supporters".
A slide in the recently released video read: "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 [sic] sites, Allah willing, and will know that we say is true. #Sons_Caliphate_Army." ©2016 USA Today