(CNN) Gab, the tiny social media website used by the accused Pittsburgh synagogue shooter that has become a haven for white supremacists, defends itself as an unbiased home for unfettered speech. But the company has itself taken part in anti-Semitic commentary, deleted tweets show.

When a Twitter user called for Gab to be shut down on August 9, the @getongab account responded with this: "Dude named 'Krassenstein' doesn't support free speech. Imagine my shock." Half an hour later, Gab's account shared a Christian Bible verse that refers to Jews who do not believe in Jesus Christ as members of the "synagogue of Satan."

In September, the Gab Twitter account posted photos of two men: Ken White, a popular lawyer and libertarian blogger, and Benny Polatseck, the founder of a public relations firm that does extensive work for Jewish interests. In the shared photo, Polatseck was in traditional Orthodox Jewish garb, his hair in sidelocks. Gab tweeted: "These two guys show up at your front door. Who do you let in and who do you call the cops on?" The account followed with: "I mean I'm calling the cops on both and getting my shotgun ready, just saying."

Some who have been monitoring activity on Gab have warned that its lack of rules on hate speech has allowed neo-Nazis and other violent white nationalist groups to share content. Michael Edison Hayden, an open source intelligence analyst at Storyful, noted over the weekend that "the neo-Nazi group Atomwaffen Division and others plotting violence are organizing on that platform out in the open."

Since Gab's inception in 2016, its founders have been open about their intention to create what amounts to a safe space for right-wing people who feel unwelcome on more mainstream social media platforms, like Facebook and Twitter. Those long-established online services are increasingly cracking down on users who attack others with racist remarks, spread xenophobic conspiracy theories about other races and cultures, and distribute hateful disinformation. Gab has repeatedly stated its mission to welcome users who engage in this kind of behavior.

"Gab welcomes everyone, but sees a unique opportunity to carve a niche in a massively underserved and unrepresented market. We estimate that there are over 50 million conservative, libertarian, nationalist, and populist internet users from around the world who are seeking an alternative to the current social networking ecosystems. These users are also actively seeking out alternative media platforms like Breitbart.com, DrudgeReport.com, Infowars.com, and others," Gab stated in a company filing dated July 11, 2017.

The social media platform has come under public scrutiny this week as it was discovered that Robert Bowers, the man charged with killing 11 people at Pittsburgh's Tree of Life synagogue, had used his Gab page to make racist posts about Jews. Bowers' final post on Gab announced his imminent attack on the synagogue.

In the wake of the shooting, Gab denounced the act of violence and issued this statement online: "Gab has spent the past 48 hours proudly working with the DOJ and FBI to bring justice to an alleged terrorist. Because of the data we provided, they now have plenty of evidence for their case. Please pray for all involved and the victims."

Gab's terms of service prohibited "calling for the acts of violence against others, promoting or engaging in self-harm, and/or acts of cruelty, [and] threatening language or behaviour that clearly, directly and incontrovertibly infringes on the safety of another user or individual(s)."

But the event caused the internet infrastructure companies supporting Gab to act. This week, Gab announced that it had been "systematically no-platformed." The website stopped working because, Gab said, it had been "banned" over the past 24 hours by payment processing firms PayPal and Stripe, as well as hosting service Joyent and domain register GoDaddy.

Two of Gab's three top executives have quit in recent months because of the public backlash against the website. Co-founder and chief technology officer Ekrem Büyükkaya, who describes himself as an anti-Trump Muslim living in Turkey, reportedly announced his departure via Gab on Sunday. "The attacks from the American press have been relentless for two years now and have taken a toll on me personally," he wrote.

The company's chief operating officer, Utsav Sanduja, told CNN on Monday he left Gab in June for the same reason. "It's really tough to govern a site with quite a lot of negative publicity, hacking, targeted harassment campaigns," he said. But Sanduja remained adamant in his support of Gab's mission to provide a social media platform for unrestricted speech, even if it included hateful, racist conspiracies and disinformation. Sanduja defended the synagogue shooter's right to post anti-Semitic posts about the mass killing of Jews, calling it "artistic expression," and said Bowers committed no harm until he announced his "imminent, lawless" attack on the religious center. Sanduja told CNN that the social media site drew the line on revenge porn, public posting of another person's private information, and explicit threats to politicians. Sanduja also said the company has repeatedly helped law enforcement gain information on users and sometimes proactively reported them to police.

The recent departure of two executive officers is a blow for a company that has, in its own corporate filings, acknowledged that it's on shaky ground. "Our ability to continue as a going concern for the next 12 months is dependent on our ability to generate sufficient cash flows," the company noted in its 2018 annual report. "No assurance can be given that we will be successful," the report adds. Gab.com, a private corporation, was attempting to raise cash through crowdfunding -- specifically by selling investors "GAB Tokens" -- which necessitated filings with the SEC.

In that same document, Gab.com acknowledged its future depended on key personnel, including the now departed Büyükkaya. It appears the company didn't even have its own office space. The Philadelphia address listed on official SEC filings was occupied by Gab.com for only a month, when the company rented space from a desk-share company in the building, according to a spokesperson to the realty company that owns the building.