A couple of Saturdays ago we told my 14-year-old daughter she could only stay out at a local shopping and theatre area until 10 pm. The curfew didn’t go over too well:

Daughter: I’m in high school now. You can’t keep me locked up.
Me: I think 10 pm is late enough.
Daughter: If you and mom keep this up I’ll rebel. And teens that rebel end up in trouble. I’ll be on the streets, using drugs, addicted to crack, and knocked up by the time I’m 18!
Me: I think 10 pm is fine.

(I will say this, I am impressed by how strong my daughter brings it when we argue.)