Yea.
One time I told the taxi driver "fuck you, you just lost your fucking tip". For being a rude piece of shit.
I was getting a ride home from the bar. Bill came to $16 (I always take this ride, so i tip $4 to make it an even $20). Anyways, I didn't have cash so i took out my visa. The taxi driver was such a rude douche about me not having cash and how the visa was such a waste of his time and shit. At first I said sorry, then he continued to get mad at me. So when the tip option came I asked him to help me bypass it hahaha.
I dont care how big of an asshole I sound like. I don't think i'm an asshole. I just tip to people who genuinely deserve it, that's what i'd want from customers if I still worked a tip job.