Officials investigating death threats to Twitter co-founder

SAN FRANCISCO (KGO) -- The Islamic state has declared a new target -- Twitter's Co-Founder Jack Dorsey.

The San Francisco company has recently shut down at least 2,000 accounts linked to ISIS and its supporters and Twitter is now investigating.

Twitter and other social media platforms are one of the primary ways terrorist groups like ISIS have spread their message. But the social media giant has recently been shutting down handles associated with ISIS over violations of Twitter's terms of use rules against violent content and that's why ISIS is retaliating.

At Twitter headquarters, security officers were on alert throughout the day, but no one talked to ABC7 News on camera about the threats.

A spokesman released a statement through email saying, "Our security team is investigating the veracity of these threats with relevant law enforcement officials."

For security professionals, this is a possible threat that has to be carefully balanced. "I think the FBI has to determine whether the veracity of the threat and whether it comes from ISIS itself or is it a message to followers to do something. That's the key," former FBI agent and private investigator Rick Smith said.

Smith doubts that ISIS has sent or can send anyone to San Francisco immediately to carry out these threats.

However, there is the possibility of a lone wolf trying to mount an attack, so Twitter will have to tighten security at their downtown San Francisco offices.

The threats against Twitter CEO Jack Dorsey were posted online Sunday on a website called, JustPasteIt.

Ian Sher covers Twitter for cnet and says the problem with online threats of any kind is their authenticity.

"Though this threat seems legitimate, it was posted to a site that anyone could have posted to and the reality is it could have been a 12 year old in Wisconsin, we don't know if it's a real terrorist or it's someone making a joke," Sher said.

What is clear is Twitter and other social media giants have recently cracked down on violent posts and video from terrorist groups like ISIS. They've removed Twitter handles and profiles.

Social media has become their primary tool for recruiting followers and encouraging independent attacks.