Why you shouldn't tip restaurant servers on your credit card. USA TODAY
When you charge a meal on a credit card, if you want the servers to be assured of their fair share, you should leave the tip in cash, more than one server has told me.
1) "Server can take that money home at night. When tips are distributed by check (often later) it's never, ever accurate. Not malicious intent usually, just lazy bookkeeping.
2) "Some owners outright steal tips," Steve says.
3) "Owners have forced waiters to give the kitchen a cut of the tips. Illegal. Instead of paying their hardest-working (kitchen) employees more, quite a few owners will steal it from the waiter. This is an old story."