All of the at-home DNA testing companies include this in their license agreements, including the ability to use your DNA in case any of your relatives might be accused of a crime. This is one case in which you definitely want to read the license before you sign up... then throw that test tube in the trash!
One of the DNA testing companies was offering a free test for folks who suffer from things like autoimmune disorders (which I do). I signed up, got the kit, filled out the survey which asks a bunch of specific questions about which particular medical condition you have, etc. I set the box aside, planning to take it to work and drop it off in outgoing mail the next day.
Well, _literally the next morning_ my youtube account was suddenly showing ads for medication for my particular condition.
They didn't even wait to receive my DNA before selling me out! Threw that test tube in the trash faster than you can say "scumbag"!