i disagree, consider this, the rich owns businesses and reaping huge benefits , chances are they are not immune to bordom so resourcing to drugs. People on welfare are very likely to be depressed, wallowing in the land of hopelessness, resource to drugs for temporary escape that i cant blame them for feeling like this. Now also consider cannabis laws, it is stupid, backwards and hypocriticial. Although I dont use drugs, not even pot (purely my choice that i prefer to have clear mind for study) i still emphasise with people who enjoy it (not chronicially that's another story - that would be akin to alcoholics, so in a sense 'cannibis-holics' (for lack fo better word just descriptive) is a problem) I still believe it should be legalised for many reasons -too much to mention in this post.
now back to drug testing i dont like it its a violation to peoples' rights to privacy, but Id say its ok for 'work-related hazards using heavy dangerous machinarys - a too relaxed mind can become a problem due to sloppy concern aorund safety. this would be as far as i'd go.
just my opinion.
back to welfare, I do not believe government should have rights to control peoples lives to this extent, it is bordering dangerously close to facism.