There is a site devoted to stories of bad customers:
These stories go back years: the site started in 2007. Reading through them they broadly break down into: stupid customers, scammers, and the very entitled. The last group of stories are the worst, now more numerous, and no doubt, as you point out, the result of growing inequality.
lyman alpha blob
The owner of a Maine diner made international news a few years ago by booting a couple of inconsiderate New Yorkers after yelling at their screaming spawn, a move which as a former waiter I wholeheartedly support. Turned out to be good for business – I work near the diner and can attest to the long lines outside waiting for a table for a while after this made the news. One other thing i like about Marcy’s Diner – it’s cash only.