"Again who is gonna check and see if she is? "
I think this is put on the parents. The idea being that to inconvience the parents enough will force them to be better parents. They can't keep her from having sex unless they watch her and keep her home after school, which means they have to be there as well. I am a believer in punishing parents for raising lousy disrespectful kids. I also approve of the judgement against piercings and tatoos. Might even make the boys cut their hair and pull their pants up. Whatever keeps them from identifying with the drug culture. We used to call it 'letting your freak flag fly'. Long hair on guys meant you were 'cool' about that kind of thing.
I have to plug here for great parenting. I'm 43. I thank my parents whenever I can for being the sticklers they were when I was 17. I hated them back then. But they loved me so much they were on me like white on rice at that age.
I met some classmates a few years ago. I was shocked to find out that some of my peers, who I used to envy for having such easy parents, had actually died of aids. I'm not making this up !
Mom and Dad gave me the tools for successful living: faith and a strong work ethic, by their example. Ya gotta be there for your kids...no getting around it.