At a restaurant in Marathon, FL, we had an ok meal, but then the dessert was delivered 'to-go' without our requesting (because they wanted to go home, at 9pm), they followed up by adding about 18% on the hand-written bill without asking, when I queried this I was told 'I guess that's the gratuity'.

I couldn't be bothered to argue, but delivered a 1* tripadvisor review that same night....

From reading the other reviews, it seems they had done this to a British tourist before.

Yesterday, in Venice, Italy, we ate in a place so infested with foreign tourists, that they decided our €120.50 bill was to be rounded up to €130, and was delivered as such. This on top of the usual (for Italy) per person cover charge.

Another 1* tripadvisor review.