SAN FRANCISCO -- Twitter has revised its rules of conduct to emphasize that it prohibits violent threats and abusive behavior by users, promising a tough stance at a time when critics are calling for the online service to adopt a harder line against extremists.
While the new policy unveiled Tuesday doesn't substantively change what's allowed, it may help Twitter answer criticism from politicians and others who say militant extremists are using the service and other social networks to recruit members and promote their violent agendas.
One advocate, however, said the real test will be how Twitter enforces the rules.
"The new rules are definitely an improvement," said Rabbi Abraham Cooper of the Digital Terrorism and Hate Project at the Simon Wiesenthal Center in Los Angeles. "But the question is: Will they be accompanied by a more proactive attitude toward making sure repeat offenders are identified and permanently removed?"
A Twitter spokesman declined comment Tuesday. In a blog post, the company said: "The updated language emphasizes that Twitter will not tolerate behavior intended to harass, intimidate, or use fear to silence another user's voice. As always, we embrace and encourage diverse opinions and beliefs -- but we will continue to take action on accounts that cross the line into abuse."
The new policy says Twitter will suspend or shutter any user account that engages in "hateful conduct" or whose "primary purpose is inciting harm towards others." The company previously said users could not promote or threaten violence and in April added a ban on "promotion of terrorism."
Under "hateful conduct," the new policy warns users: "You may not promote violence against or directly attack or threaten other people on the basis of race, ethnicity, national origin, sexual orientation, gender, gender identity, religious affiliation, age, disability, or disease."
The new policy also explicitly bans "creating multiple accounts with overlapping uses" aimed at evading suspension of a single account. Critics say Twitter has previously made it too easy for extremists to create new accounts as soon as older ones are shut down.
The Islamic State of Iraq and Syria (ISIS) has used social media to recruit tens of thousands of fighters from around the world. It has been estimated that ISIS and its sympathizers run as many as 90,000 Twitter accounts.
After the San Bernardino shooting that left 14 people dead, President Obama called on "high-tech and law-enforcement leaders to make it harder for terrorists to use technology to escape from justice."
In the days following the shooting, a federal law enforcement source told CBS News that Tashfeen Malik, one of the attackers, pledged her allegiance to ISIS leader Abu Bakr al-Baghdadi in an online posting, CBS News senior investigative producer Pat Milton reported.
The Department of Homeland Security told CBS News correspondent Jeff Pegues earlier this month it began three pilot programs in 2014 to examine whether screening social media was consistent with current laws and privacy protections. A review of the policy is underway.