Good advice: Never answer a number you don't recognize. (These guys called my unlisted number this morning, and I didn't pick up.) As for the person who called them back to check: Huh? All you're doing is confirming that yours is a valid number. This doesn't do you any good, but you're doing the scammers a big favor. There are also those innocent people whose numbers have been appropriated by the scammers for phony Caller IDs. Bothering and berating those innocent people will do you no good at all.