> Here in Germany "Mein Kampf" is illegal to sell.

It's not that simple. (in short, unedited and uncommented reprints are problematic (but not directly established as "illegal to sell" currently I'd say), pre-1945 printings are fine, commented editions exist and are fine)

A commented edition was published recently (within last two years), but iirc it was the first of its kind?

Edit: pasting comment to post below here, because HN doesn't let me post

It seems this state of affairs was quite convenient for the government, and when the copyright expired, they decided to continue making it not legally available: https://www.spiegel.de/kultur/gesellschaft/adolf-hitlers-mei...

Seems to be true that it could be sold in antique shops and offered in libraries (not sure if any did offer it).

Until 2016 all new printings were stopped on copyright grounds by the state of Bavaria. Hitlers registered address at time of death was in Munich, so the state of Bavaria acquired his assets and used that to stop printings (internationally not often successful, and with the exceptions of US and GB, where the rights had been sold to Random House by Hitlers publisher), but 2016 (70 years after death of the author) the copyright expired. Copyright was fairly straight-forward legally, commented editions now are too.

Why go as far as usa when it's readily available at libraries and for sale in many many European countries? Even some versions with comments are legal in Germany itself.

Because it is a point about free speech in the USA (facebook being a US company), not availability of the book in other countries.

Significant events in US history, such as the Abolitionist movement, women's rights, the Civil Rights era, et cetera, would not have been as easily accomplished without freedom of speech being defined the way it has been in the US.

The fact is, you can't have freedom of speech if your also not allowing people to engage in hateful speech, no matter what most "progressives" would tell you.