Originally Posted by
sethb
This has gone to court several times, and each time the court ruled that the airline/hotel is the owner of the miles/points and has the right to cancel the account and confiscate the miles/points. In some cases, the airline also canceled tickets that were purchased with those miles.
Given the MS situation, that could be changed.
(Note - AFAICT, those cases you mention should largely involve contract law, but not tax law. So the interpretation may be different.)