> Gab's users have a disconcerting tendency to blow up synagogues.
The Gab user in question was issuing threats on Twitter as well for months. Twitter did nothing about it. Under your exceptionally poorly formed argument, Twitter's users have a tendency to blow up synagogues (it was actually a shooting).
Under your premise, Twitter and Facebook should be forced off the Internet, or otherwise maligned, because the people that commited 9/11 were Arabs and there are Arabs using Twitter and Facebook. Under your premise, all Arabs should be guilty and share responsibility. Because N number of Arabs threaten Jews, no Arabs should be allowed on Twitter or Facebook, or otherwise those platforms must be isolated. You could widen that and claim it should apply to all Muslims because of some bad Muslims. By your premise all Muslims share guilt for the actions of some Muslims. See: Louis Farrakhan on Twitter.
We can extend your absurdity further. We can start talking about how Facebook should be shut down because it was used in some manner to assist in genocide in Myanmar. All chat applications must be destroyed, all encryption must be removed because it could shield someone like the Pittsburgh shooter. The iPhone and its security has to be forced out of existence, lest it protect someone like the Pittsburgh shooter. Why just imagine all the horrible conversations and plots that have taken place online, shielded, aided by encryption. Your premise has to be that encryption is also evil and must be 'stopped' or outlawed, because it routinely assists evil deeds.
And that's before we get to the use of encryption in warfare. Command & control, drones, planes, bombings, satellite communication. Essentially all warfare now or in the near future will be heavily utilizing encryption technology in a critical manner. That's a very large amount of killing and murder, in other words. As a technology assistant to evil, Gab couldn't hope to rival encryption tech in a thousand lifetimes. Your premise would require the abolition of all encryption and that all engineers and service providers globally must stand against all encryption technology. Such that we can see what all people are doing at all times, since so many evil people utilize the Internet and encryption.
It's a very obviously absurd premise you're floating. The entire Internet has to be destroyed if one follows what you're saying to its logical conclusion.