Apparently I'm something like 10,000 in line to join gab.ai -- seems like this week's hot new social network. Here's to freedom of speech & no censorship! It'll probably fizzle out though like Ello did
Reading the terms of service and community guidelines, I'd guess USA. They follow DMCA and ban terrorism (as defined by the US government). As for garaunteeing, well that's more tricky. The fact you have to login to see anyone's posts is possibly one way to do this. It's harder to argue the site should take some content down when it's behind a login.
Very few networks are truly censorious, so I am not sure if it is a good pitch. I've also seen better privacy policies. The anti-harassment tools do sound interesting though. And I agree with the sentiment of letting people chose what they wish to see and what not.