Tests are easy to get around, very easy, i cheated on random drug tests many times when i was in the army, ive also got quite a few friends in the marines, army and air force all using gear and have never been caught, theres ways round it. As soon as you see the drug test officers shutting the gates, take your precautions.
I was on a drug free wing also when i left the army and did a spell of prison because i didnt want to mix with all the smackheads and i got tested twice a week on there, passed every time, once i even used drops of tea in hot water stored in the finger of a plastic glove i kept in the waistband of my boxer shorts and even that passed, the only people who get caught on drug tests are the ones volunterily handing in there own drugged up body fluids.