DNA is vastly different from your name and address, which many would consider public information. DNA is much more identifying and private.
Personally, I have to trust someone much less to send them a photo, than an address of residence.
I'm not exactly sure what can be more undesirable - being recognized or being physically interacted with. However, my first impression when I started to reply to your comment was that it's the latter.
Please state your argument in full. Statements like this are just further FUD.
In the case of markers like this, it's pretty easy to correlate by race or other heritable factors criminal behavior. If there's no harm in it, when a crime goes down in an area it seems reasonable to go and just round up all the people with rough genetic markers matching, right?
It might even make sense to keep them in groups organized by genetic markers and race, since that should speed up policework dramatically.
And later, if you want to procreate with somebody, maybe you should make sure their genotype won't mark your kids for poor treatment by the authorities--after all, accidents _do_ happen, and the labwork is never 100%, so better safe than sorry.
Can you see why this makes people antsy?