The second order effects are obvious and negative. Fewer people will report crimes if doing so requires putting their DNA in a government database. If more crim

The second order effects are obvious and negative. Fewer people will report crimes if doing so requires putting their DNA in a government database. If more crimes go unreported then everyone is less safe. For example, say the police routinely collected and stored DNA from burglary victims in the course of burglary investigations. If that makes people likely to report burglaries then it's possible the burglary she was arrested for might never have been reported in the first place. If fewer crimes are reported, fewer criminals are caught. Even if you yourself are perfectly comfortable putting your DNA into a government database as a prerequisite for reporting a crime, you may be less safe overall if others do not feel similarly.