You cant totally blame the parents for everything, while alot of times it is the parents fault, and they lack just that, parenting. But others do try their best. You cannot possibly supervise your kids 24/7, sooner or later its time for school, or bed, or you have to work when they are off from school. Kids today are smart, and know how to get around stuff. I say this because my parents where very strict, and tried their asses off to get me to stay in school, and do work, and be an overall productive member of society, but they more they did, the more I did to get around it all. When I was in middle school they wouldnt let me listen to 'parental advisory' CDs, but instead of not doing it, I was giving my lunch money to fellow class mates for burnt copys of the CDs their parents bought for them. When I was in HS, my parents were so carefull about me not getting a chance to try smoking, even going as far as not letting me hang out with ppl they didnt know the parents of. Well my first smoke came from a pack I found next to a bench in the park THEY took me to. Next they put an alarm system in so I couldnt sneek out at night, well during the day when they werent home, id take the batts out of the alarm sensor on the door I would use to get out, they were none they wiser, and if they would ask id say 'how could I have with the alarm system'
My point is sooner or later someone, anyone or anything will allow your children to do things you dont want them to. You search your kids rooms for smokes and drugs, but dont realise the high powerd laser on the dresser, you cant watch for every little thing, it cant be done. You have to educate the kids as best as possible about what to watch out for, but even that, you cant teach them everything, they just dont understand, like the girl with the laser, she figures if it will burn walls it will burn her eyes, she doesnt understand how the eye works and why the laser hurts it.
Heck, while your reading my post, your kids could be in the other room on a computer you dont even know about, using money you didnt know they had, to order god knows what off the internet.