Yes but with a complete DNA database you can match an external sample exactly to the database with (near) complete accuracy. The DNA database doesn't tell you a

Yes but with a complete DNA database you can match an external sample exactly to the database with (near) complete accuracy. The DNA database doesn't tell you anything itself. With a database of all communications you have to mine it for probabilistic leads. The signal to noise problem grows as does the database. Someone else (I cant recall who) said - the last thing you need when looking for a needle in a haystack is more hay.