Without getting into too many details in the wrong forum, some may perceve a benefit (or Continental's lates't euphimism for reductions, the "enhancement") as a far worse deal than what they were getting.

If you sell shoes, put a pair of Itallian oxfords on layway for someone, and at the end of the 20 payments, give them a pair of Hush Puppies instead, that's consumer fraud - bait and switch after having received money for one specific product an trying to give the consumer another.

If the airline says after 1K miles you get 5 systemwide upgrades, they let people approach 1K miles, and when they get there, they say "sorry, this year it will be 2 systemwide" that's the same consumer fraud - bait and switch.

If the airline says it's "enhancing" it program (to use the latest examples from One Pass) that you no longer have to call-in for upgrades as they will be automatically applied (when yield management feels like releasing the seats) many lower level elites flying transcon were "enhanced" right out of their upgrades. When they say that International Mileage upgrades are "enhanced" to be less confusing - when they are really now restricting the upgrades to only H K and Y fares, many are feeling "enhanced" out of this benefit as well.

And please, don't make the arguement that the airline is selling only the seat and transport, and once providing it, their responsibility is over. If they choose to market their FF programs as an incentive, then they are just as responsible for providing these services in a manner that does not constitute consumer fraud.