Experts say anti-PDA policies have existed for nearly two decades, although it's not known how many schools and school districts have imposed such rules.
Have things lightened up since 2007? Not as far as I can tell. I googled "detention" "display" "affection" and immediately found many examples of current school handbooks that spell out the consequences for hugging, holding hands, kissing, etc. It ranges from a warning up through suspension, depending on how many times you've offended. One school even allows for expulsion upon the sixth offense. (Here, here, here, here, here, here, ... you get the idea.)
Enforcement must have been lax or only just getting started in the early '90s. I remember girls hugging each other, and guy friends hugging their chick friends. My first French kiss was in 6th grade, spring of '93, inside the cafeteria after school. Groups of us used to hang out in the cafeteria, outside, wherever, without belonging to a club or other activity. And I don't remember getting harassed about it. If they had been dead set on preventing the slightest hint of inappropriate behavior, we definitely would not have been allowed to hang out like that.
Then there was the time when we were coming back from a field trip on a chartered bus, and as usual me and my friends are sitting way in the back. Across the aisle is a couple, and out of the corner of our eye we see her slip her hand into his pants. Word must have somehow reached the front, because after a couple minutes a teacher marched back and asked the guy to move up to the front and leave his gf where she was. He didn't get detention or anything either. That was 7th grade, spring of '94.
I also remember the chaperons trying to impose a certain distance between us when a boy and girl partnered up at the school dances. But we went right back to wherever we felt comfortable once the chaperon had moved on. They don't have to worry about that now because young people have no interest in dancing with each other -- indeed, would feel creeped out by letting another person into their personal space like that, especially with their hands touching your hands or maybe even your body. Ewww, like omigosh -- creepy!
That's only what I remember from direct experience. I'm sure the other kids who went to middle school with me have similar memories. Our group was more rebellious (by middle school standards, mind you), but that couple who got caught on the bus were part of the preppie crowd. I think the only ones who wouldn't have memories like that were the nerdy/dorky groups.
BTW, have you noticed that it's always the dorkies, uglies, and fatties who commit PDA after high school? Not like normal stuff, but exhibitionistically trying to rub everyone else's face in it. Like, "You thought we'd never find anybody else -- BUT WE DID." You know? Like, "Take that, society." Yeah well you're still losers, so go away before you make us barf.
Anyway, my hunch is that the ban on touchy-feely behavior really ramped up once the Millennials hit middle school in the late '90s. Gen Y didn't have helicopter parents -- not only during the '80s when the breed didn't exist, but right through high school and college, when they did. It's like your parenting style congeals forever in the immediate lead-up to the kid's birth and just after, although it may therefore vary from one of your kids to the next.
So our parents weren't too paranoid about us huggin' and a-kissin' in middle school, even though the helicopter parent phenomenon had already taken off among parents of younger children. Once the helicopter parents were parents of middle schoolers, though, it was game over. It seems like the same with high school -- it was definitely lamer in the late '90s compared to the '80s, but not because of meddling parents so much. The whole culture, including young people, was dulling down. Once the Millennials got into high school, though, in the 2000s -- fuhgeddaboutit. Then the helicopter parents could trash high schools as well. Ditto with colleges starting in the mid-2000s.
The Time article does say that there was a surge in writing up anti-contact codes in 1999 and afterward, though they attribute it to a then-recent Supreme Court decision that said schools were responsible for maintaining a harassment-free environment.
Sure, schools must have felt like they were liable and needed a CYA policy, but that didn't need to wait until 1999. That whole anti-harassment witch hunt had been brewing since the early '90s at least. But parents in the early or perhaps even mid-'90s weren't the type to sue over Bobby and Susie hugging each other. Only when the school board met the helicopter parent army did they piss their pants about students hugging on school grounds.
It really is striking and sickening how far the parents of Millennials have been willing to go in order to prevent all outside influences from corrupting the code that they've spent their life programming into their robotic child. You can lock them indoors until they're 25, and keep them from going out on dates -- but what about if they wanted to "date" somebody at school, and get close to each other there, away from your watchful eye? Send in the principals, and crack down. If you've ever wondered why you never see young people falling in love with each other anymore, here's part of the reason.