@TigerUK, some UK employers drug test too, but only when it's safety related (pilots, train drivers, air traffic controllers).
Otherwise, it could fall foul of privacy/human rights law.
This thread has highlighted something interesting for me: US & Europe have very different priorities in what the consider to be inviolable rights.
For example - the Europeans have much stronger privacy protection. As far as I'm aware, there is no US federal equivalent to data protection acts, or human rights legislation.
US law, by contrast places more emphasis on freedom of action, such as free speech & gun ownership. In most of EU, there isn't a strong protection for free speech (although it's certainly not prohibited), and gun ownership is curtailed.
Not saying one is better than the other, just noticing.
EDIT: oh, and JJ technically acts as a private arbitrator, not a judge. Most jurisdictions have provision for enforcement (e.g. making people pay) of arbitration awards in their civil code these days, but she can't send anyone to prison.