Will Baude points out:

Fischer certainly seems to be a rather strange guy, possibly in need of serious help, but I’d just like to remind readers that the federal charges Fischer faces are for playing an illegal chess game!
Sadly, the freedom of chess is not yet protected by the Constitution.

This actually illustrates something I think of as an important freedom, one which is treated very differently on the two sides of the Atlantic. Surprisingly, it is a comparison in which the US comes off worst, not the normal state of affairs.
Every country claims the right to impose sanctions and to limit trade with certain places or regimes at certain times. However, the US goes further, insisting that it is allowed to make it a criminal offense for one of its citizens to even visit certain places. This is completely unheard of over here. For example, the UK Govt may advise you not to go somewhere, may point out that it can’t help you if you get into trouble, may play up the dangers of a place, but is has never even dreamed that the Govt of a free country might try to tell citizens where they may or may not travel across the planet. The US does, much to its discredit.