A recent hacking attempt reminds me that many people won't use their their credit cards on the internet at all, but have no qualms about handing them to a waiter. The Dilbert Cartoon below shows the fallacy:

Drudge's headline

Cops: NYC waiters stole $1 million in credit card scam...

shows that this can happen in real life. I have no idea if any of the waiters involved were immigrants, but most New York waiters are, many illegal.