Former Democratic National Committee chairman Howard Dean said late Sunday that Gab, the social media platform used by the suspect in the Pittsburgh synagogue mass shooting, "should be tried for being an accomplice to murder."

"You are a facilitator of neo nazis and other haters. You should be tried for being an accomplice to murder," Dean, a former governor of Vermont, wrote in a tweet. "You're lucky shutting you down is all you get. A lot luckier than the 11 Jews in Pittsburgh were or the two African Americans murdered in Kentucky were."

Dean was replying to a tweet from Gab that called on President Trump to "ACT" after the social media company said it had been "no-platformed" by online companies including Paypal and Stripe, two payment-processing platforms. Gab said it would be offline until it can transition to a new hosting provider.

Gab has been criticized for allowing right-wing extremists to use the website. The social media platform describes itself as "The Home Of Free Speech Online."

Robert Bowers, the man charged in the shooting deaths of 11 people at Pittsburgh's Tree of Life synagogue, wrote on his bio on the site that "jews are the children of satan." His bio also included an image with the number 1488, a reference to Nazism, according to The New York Times.

In a statement Saturday following the shooting, Gab denied any responsibility for the shooting, saying that it has "zero tolerance" for terrorism and violence.

"Gab unequivocally disavows and condemns all acts of terrorism and violence. This has always been our policy. We are saddened and disgusted by the news of violence in Pittsburgh and are keeping the families and friends of all victims in our thoughts and prayers," Gab said, adding that it has been "smeared by the mainstream media" for defending free speech.