Earlier quoted context omitted.
> One particular one: Insurance companies audit for such employees, and either cancel insurance or raise it to unaffordable rates. Never been to the States, but shouldn't there be a law against this?
No, there isn't. Convicts are one of the last remaining class of people not protected by law. Every time any effort begins to make convicted folks a protected class, it makes politicians appear weak on crime and is quickly silenced.
Yes, there are laws and court cases that should change the outcome, but that means a lawsuit.
In other words, US employment frequently comes with a lot of implicit assumptions about your lifestyle.
Edit to add: fortunately random drug tests aren't very common in the tech industry.