The amount of times I have to warn users that freedom of speech, as we commonly understand in the US, may not be a thing in their country, is out of this world.

Call it Holywood brainwashing or whatever you want, but there is a lot of people outside the US that think the US law and their country's own law are similar, if not the same. And that is a dangerous assumption to make.

Point in case: There is no general right to free speech in the UK. Many examples of British law violate the US's first amendment. Today's freedom of speech law in the UK is a side-effect of their membership into the European Union. Until now, the UK Parliament has chosen to exercise self-restraint in which speech should be prosecuted. But that can change with the political will of that institution, especially now that it is not part of the EU anymore. US's first amendment, on the other way, cannot be easily changed or limited by congress.