Because it's based on a recent special law for teachers. Lots of Alabama teachers have sex with their high school students. I mean a lot of them - don't believe me? Google it, it will blow your mind. But, they weren't able to prosecute most of them, because the age of consent in AL is 16. So you had lots of 30-40 year old banging high school kids, and there wasn't anything the DA could do about it. Sure you could fire them, but that was the extent of the public's recourse for these pieces of sheet. So, recently AL passed a law that says you can't screw your student if their under 19. Welp, lots of teachers are still out there just a gettin it, and this law is to make sure they all understand that just cause she or he is sixteen doesn't give you a free pass, if you're that person's teacher, keep it in your pants, or his pants, as it were.