WASHINGTON — Islamic State group hackers have threatened two Silicon Valley tech titans, posting a 25-minute video online that shows bullet holes over the faces of Twitter’s Jack Dorsey and Facebook’s Mark Zuckerberg.
Both companies recently stepped up efforts to block postings and accounts that promote violence and Islamic State group propaganda after months of criticism from Obama administration officials who complained social-media companies weren’t doing enough to smother extremist recruiting online.
The apparent peril for two social-media pioneers is the latest worrying intersection of extremist propaganda and the fast-evolving digital technology and online global presence that Twitter and Facebook represent.
The Islamic State group displays “unprecedented online proficiency,” James Clapper, director of National Intelligence, warned the House Intelligence Committee on Thursday at a hearing devoted to national-security threats.
In addition to organizing or sponsoring deadly terrorist attacks in Europe, Canada, the Middle East and North Africa, the Islamic State group and its affiliates have used social media to recruit followers and encourage “lone-wolf” attacks by homegrown violent extremists on the United States and its allies.
The married couple who shot and killed 14 people in San Bernardino, Calif., on Dec. 2 had pledged allegiance to the Islamic State group leader that morning on Facebook, for example. But they had no known contact with the group.
In May, however, the group claimed direct responsibility for the attempted attack on a Prophet Muhammad cartoon contest in Garland, Texas. Both gunmen were shot dead.
This past fall, FBI bulletins warned that the Islamic State group was promoting attacks against law-enforcement personnel, members of the news media and the U.S. military. The agency urged service members to “review their online social-media presence for any information that might attract the attention of violent extremists,” including home addresses.
The latest video, purportedly created by pro-Islamic State group hackers calling themselves “Sons of the Caliphate Army,” was shared on the messaging app Telegram and was first reported by the online-media company Vocativ.
“If you close one account we will take 10 in return and soon your names will be erased after we delete your sites, Allah willing, and will know that we say is true,” text in the video reads.
Twitter announced Feb. 6 that, in the previous seven months, it had deleted more than 125,000 accounts containing extremist material.
It’s not clear how effective that effort has been. Islamic State group supporters have been known to quickly replace deleted accounts with new Twitter handles.
Facebook also has taken down offensive pages, and Zuckerberg has publicly supported the campaign against terrorist groups. “We feel a pretty strong responsibility to help make sure that society is safe,” he said in a speech this week in Barcelona, Spain.