The microblogging service Twitter has suspended the account of the al Qaeda-linked Somali militia known as al Shabab.
The move was made after the terrorist group used its Twitter feed earlier this month to threaten to murder a French hostage and again last week to threaten to kill Kenyans they had kidnapped.
Twitter’s press office failed to respond to several requests for comment Monday, but al Shabab’s page has been unavailable since Friday. “The Twitter Rules” for the microblogging site read in part: “You may not publish or post direct, specific threats of violence against others.”
The move appears to mark a policy shift from Twitter, which previously has refused or ignored requests to take down feeds used by terrorist organizations. Both the Taliban and several al Qaeda affiliates have official Twitter feeds that link to their press statements and Web releases.
In the past year, extremist groups have made increasing use of Twitter and other social networking sites after many of their traditional Internet channels — password-protected private chat rooms — closed because of sudden and unexplained technical or security problems.
The Simon Wiesenthal Center — a Los Angeles-based nonprofit group that monitors use of the Internet and social networking by terrorists and hate groups — plans to put Twitter on the cover page of its annual report, to be published in March, the center’s associate dean, Rabbi Abraham Cooper, said Monday.
“And not in a good way,” he said. “If I was grading [social media sites for blocking content that promotes terrorism], Twitter would get an ‘F’.”
Unlike FaceBook Inc. and Google Inc., which owns YouTube, Twitter has no easy way for users to flag content they believed might be in violation of the site’s rules, Mr. Cooper said.
“I call it the Wizard-of-Oz effect,” he said. “We don’t know who’s behind the curtain.”
“The other sites, like FaceBook or Google have developed institutional ways to respond,” he added.
“They have a set of rules. They have a staff team that looks for violations. They take down thousands of pages. It gives groups like us, or any individual user, a place to go to get an answer. ‘Will you take this down?’ We might not always like the answer, but at least we get one.
“If Twitter has a policy [against feeds that promote terrorism], they keep it a secret,” he said.
J.M. Berger, a terrorism analyst, also noted that Twitter’s rules are much less restrictive than the terms of service for other social networking sites.
“The rules are really, really broad,” he said. “You can put up stuff you would never see on YouTube or FaceBook.”
Mr. Berger, an avid Twitter user with thousands of followers, was one of the first to note that al Shabab had, as he put it, “stepped way over the line even for Twitter.”
On Jan. 16, the group said in a tweet they would execute Denis Allex, the pseudonym of a French intelligence officer they captured in Somalia. French authorities said he was already dead, killed in a failed rescue attempt five days earlier.
Last week, Mr. Berger tweeted that al Shabab threatened to murder Kenyan hostages. Two days later, the feed was taken down.
Mr. Berger said he had seen individuals or groups suspended from Twitter but could not recall the service removing a terrorist group.
“They recently took down some neo-Nazi feed that the German government had singled out,” he said, noting that it is against the law in Germany to promote Nazi ideas or symbols.
France had expressed its displeasure about the al Shabab feed after the group posted pictures of the mutilated corpse of a French special operations soldier killed in the failed attempt to rescue Mr. Allex, Mr. Cooper noted.
“It’s a shame if it takes lawsuits and pressure from governments like Germany and France to make Twitter do the right thing,” he said. “They should have been on top of this a long time ago. It’s not a theoretical issue about freedom of speech. It’s a life-and-death issue about terrorism. It’s no secret Twitter is used by terrorists for command and control.”