Also, what is fucked up is that even if you NEVER use one of these DNA ancestry sites, the police can use their database to find Familiar DNA...say from a 3rd cousin, who DID send theirs in and is in their catalog, and use THAT information to identify evidence DNA, then use THAT familiar match as Probably Cause to obtain a search warrant and force you to give your DNA.

Basically Illegal Search and Seizure by proxy.