Well, I have, actually. There are heir-hunter scams. You're contacted by someone claiming to be from a lost heir hunting company. These companies claim to track down the closest relatives to people who died without known heirs, in return they get a share of the inheritance. So you can't bypass them, they won't tell you who you're supposedly the heir of. They promise they're not asking for money, only a share... until they do ask for money, of course.

This scam doesn't use your actual DNA data though, just the fact that you have a profile on a DNA site.