The problem is, as stuff becomes easier and cheaper, usage becomes more widespread.
DNA tests used to be in the many thousands of $ range, so they were used for heavy crimes like murders and rape only. Nowadays, it's routine for police to use them for petty crimes like graffiti [1].
It's just the same for camera surveillance, mass exfiltration and analysis of just about the whole Internet's worth of traffic... even searching phones and datamining them is cheap enough these days that US CBP does it for travellers, and German authorities for refugees (until a court order stopped that crap [2]).
