at this point I can't obviously imagine my daughter ever doing drugs hence its not something I can ponder over for myself but I cannot judge parents who do go through such desperate measures. See I know of families where despite parents assuming they share wonderful close relationships with their kids, and also assume their kids to be God fearing and moralistic etc, finding out horrible things about what their kids had actually been upto. Many times when teenagers get themselves into such evils they also become masters at hiding their vices from parents and those around. And if a parent feels with a conviction that their kids might be hiding terrible truths from them, and that merely interrogating them will not do,then they might have to go through such measures to ensure their kids safety. Lets face it..times are not getting any better. So its up to each parent to do what they believe is best as long as it saves the kids!