Can you imagine Snapchat without teenagers? Soon, in Europe, you won't have to imagine it, as the number of teens using the service is sure to drop dramatically.

Among the many provisions of the new European data protection rules announced Tuesday is one that blocks anyone under 16 from using any service that collects data about them, unless their parents formally agree to it. That means most teenagers would disappear from Facebook, Snapchat, Twitter and Instagram. We'd be left with an allegedly more mature audience, which would certainly be a change. The changes are scheduled to go into effect in 2017.

While it’s not clear how exactly how many people younger than 16 are using social media sites in Europe, or how many parents are okay with it, there’s no doubt that the new rules will affect a big chunk of these companies' user bases. Teenagers are also uncommonly attractive to advertisers, partly because many have disposable income, but no financial obligations.

So from a business point of view, this has got to be bad news for the big social media sites. In time, it may get less dire, because the E.U. is giving its 28 member countries the ability to set their own age restrictions, and some may opt for an age younger than the pan-European ban.

Whether or not the news is good for the teenagers themselves is harder to know. Many parents allow their kids to use social media on the condition that the kid fork over their user names and passwords, enabling the parents to keep an eye on what’s going on. You could describe this as social media with training wheels, and make the argument that it's helpful for kids to learn to use social media under the eye of an adult.

At 16, though, it's a lot harder to convince that same kid to give up his or her passwords. They're more likely to have their own electronic devices, and it's a lot easier for them to exclude their parents from their social life--online and off. They're pretty much on their own.

This is, curiously, one of the arguments often used to defend a lower drinking age--that an 18 year-old may start drinking at a social function with a parent, family friend, or even a professor, where pretty strict social norms are in place. Change the drinking age to 21, and you’ve got a bunch of young people, with no supervision, drinking grain alcohol.

I personally am thankful to have made it through adolescence before the likes of YikYak, and frankly wish today's kids could do the same. So part of me is relieved to see the EU making what seems to be a sensible stand. Sixteen is a lot different than 13.

On the other hand, I grew up as a straight white girl with a loving family in a town that appeared to be mostly other straight white people. There are way too many adolescents who live with adults who don’t look out for them, or who are ostracized because they don't fit certain cultural norms. Those kids desperately need to find their tribes, and without social media, it's going to be a lot harder.