Have you considered not selling technology to cops?
But also, I have mixed feelings about this from a moral/ethics perspective. I think it's going to do more harm than good by making testing easier and more prevalent (we already have blood tests for cases where someone was injured by a driver, etc.). The good thing is it may save some regular users from being labeled as impaired versus a blood test. Outside of that small case it all seems bad for society to me..
You'll note that most people angrily report their bad incidents with cops; when they're doing their job it goes unremarked. Not too far off from good IT support.