Under swiss law, when I joined Mileage Plus (offered by UA Zürich then) UA would have to provide me the rules/general conditions etc of their programs in one of the four official languages in Switzerland (German, French, Italian, Romantsch). They didn't (and couldn't at that time).
And I don't think I ever signed anything that I would like to see how US law should 'govern' over me when asking/buying/selling/offering Mileage Plus awards from/in Switzerland. May be I really should barter or sell/buy an award, and then officially report it to UA, and then hoping to have all the fun of reporting on this board afterwards on the legal consequences
Again, I love this discussion, but in general I really give away awards and miles as real presents/gifts

(at least about 25 Flyertalkers could confirm this).
I find it somewhat funny the way a majority of my North American friends on and off this board, find it illegal to barter awards, but don't mind to lie daily (security-questions) when asked at check-in if they were in controle of their luggage etc (but they might have used a bell-boy, or left the luggage unattendet in the hotel room/lobby during breakfast, etc. etc.). PremEx, some time ago, replied to this thruthfully: yes,
UA made me a 'frequent liar'!