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I just don’t agree. the dna isn’t automatically added to GED match. people have to choose to opt in, or they are made aware when they submit their dna that it will be available in those kind of databases. genetic genealogy has resulted in decades long cold cases being solved. it could very well lead to wrongfully convicted people being exonerated.
I think you need to read up on what genetic genealogy is and how it’s been used in cases. Cece Moore is a good name to look at - this is a laborious process and leaves essentially no room for error, and needs to be confirmed with a fresh dna sample (ie discarded cup or cigarette). people are acting like genetic genealogy is being used to catch innocent people or to catch people committing very minor crimes. this is largely being used to solve decades old cold murder cases and serial killer cases. if we had good dna on the zodiac, he would have been caught by now with this technology. 
no one is telling you to submit your dna to GED match. personally I would have no problem with a distant relative of mine being caught using mine if they committed a violent crime like the ones being solved here.
I bet it’s like how they caught the golden state killer. Run it against the database to a sample at the scene, hits on a family member. They can tell they’re related from the DNA profile but it’s clearly not the person in the system. Look up relatives, wow he lives 10 miles away, look up registration, drives an Elantra. They tail him across the country for in PA till he throws away a drink cup or something, watch him use it and toss it, it’s abandoned property. Test the sample- boom, match. Arrest warrant. >

This seems like parallel construction with extra steps, but I'm no supreme court judge. >

absolutely not - most states hold that discarded items are fair game for law enforcement. no way a challenge like you’re suggesting would ever hold up in court. >

I'm not contesting the legality of it, I'm no lawyer type. But morally it feels like it should be poison fruit. And it isn't, but that feels like a gap in privacy law, at least to me. >

don’t agree at all. you discard something it is fair game. what right do you have to privacy over an item you’ve discarded? none. people have tried and failed to challenge the legality of this kind of evidence. it’s been used in dozens of high profile cases >

Let's wind back to clarify what I mean. I believe that morally, performing investigation via genealogy database records is a bad idea. I think it is against societies best interests. I believe that it will open the door to police overreach and will disincentivize people from using important genetic services. This point can be easily debated.
But given that I think that that, using genealogical data to find nearby relatives, whose only fault was being geographically close to the crime and a relative of someone who is a potential DNA match feels morally dubious.
Again, I'm not claiming that it is against the rules, I'm asking whether perhaps it should be.