Couldn't agree more regarding your points and those of other posters about the current government however I don't feel this is a good enough reason to throw the baby out with the bath water so to speak. I think drug policy in general has to change as we are far behind other countries in how best to manage these problems and sadly are developing some of the highest rates of usage in the world.
I hate to say it but this information may be a government plan to assess the problem, ie getting hard figures on rates of use etc so that specific groups can be identified and targeted for early intervention. Also there is an addicts register in existence of course however I really don't know whether identification through drug testing is going to end up giving you a label on some government database, presumably so, somewhere, and who knows where that could end up or who would have access to it, and this is a concern.
Will it be a good thing? Only time will tell, but I think that the unemployed are fair game for drug testing just like everybody else.
The times they are a-changin.