Originally Posted by
Nugget_Oz
The practice of slavery in the U.S. was long-established and well-known, still does not make a practice right and there are U.S. residents who do not tip as a matter of practice which they should be entitled to do. There is a legal argument that it could well be extortion and the Skycap practices could be subject to the RICO Act but it's a question of whether any individual is willing to take the necessary steps to bring such action.
Tipping is not extortion and comparing to slavery is, to put it charitably, beyond ludicrous. People in the U.S. who don't tip are few and far between, but they are just as much boors as the foreign visitor who refuses to do so.