My brother bought 23andme for my parents last Christmas and I thought it was kind of funny, because it was essentially having us submit our DNA to a database that will outlast all of us. Later on I found law enforcement have been successfully using it to solve crimes, especially murders and heinous crimes which is fine. Don't go out committing serious crimes, because in this day and age you will get caught. One way or another, society is so advanced, and technologically sound the margin of error for criminals is almost nill, barring a miracle.

Why not imo, don't go out committing serious crimes and you have nothing to worry about. Now id change my position if down the road they start using these databases to solve any crime, even minor ones. Then id have a problem with it, but seems they mostly rely on all of this in the most serious of cases, so its fine imo.