The 'politics' of tipping aside, one thing that really grinds my gears is that they calculate the tip after taxes are applied. I feel that the tips should be calculated based on the exchange I had with the establishment/person and that the taxes should considered separate from our interaction. Like, here's the 20% tip on the 100$ I spent. Not, here's the 20% tip on the $100 + 5% tax, $105 total. I know why they do this, it's more money to them, but, to me, it's disingenuous (or they don't realize it being done this way, which may be worse).