Among the children product makers, it is known that US government go crazy with COPPA, throwing huge lawsuits even against mom'n'pop shops if they think you are somehow not meeting COPPA fully.
Even my business, that has NOTHING to do with the USA (our dev lab is in Brazil, our headquarters is in Switzerland, and we sell to Russia, Brazil, France, Germany and Korea) we comply with COPPA because we fear USA might find a way to screw us.
When dealing with USA (that I don't know why its citizens still believe is land of the free) it is ALWAYS better to go safe than sorry.
Children have been misrepresenting their ages since well before COPPA was introduced, but I distinctly remember COPPA making the problem much worse amongst my peers.
I remember, a few weeks before one of my birthdays, having to pick between abandoning my Neopets account so that I could create a new one where I pretended to be over thirteen, or asking my parents to sign a printed permission slip for me and each of my sisters and let me fax it to Neopets.
I ended up doing the latter, but only because I knew we had a fax machine in the house, and my parents already knew (and were okay with) me being on Neopets all day long. A bunch of my peers just created new accounts, and eventually devolved into sock-puppeting once they realized that there wasn't necessarily a one-to-one correspondance between people and accounts.
I'm not sure what the right answer is, though. The moment that a child turns 16, 18, or 21 (depending on jurisdiction) they're inundated with peers who want to go on Facebook, offers for loyalty programs and credit cards from every store they visit IRL, and tracking cookies from Ad networks online. If a kid has $20, and wants to buy something from the local Wal-Mart, no one will stop him/her from doing so. But if a kid wants to spend that $20 on Amazon.com, COPPA prevents them from even creating an account in the first place.
As a kid, I felt like COPPA simply prevented me from participating in the world in a way that nobody would have ever experienced before dial-up became mainstream, and I seriously think that harmed my ability and that of my peers to handle the privacy concerns that plague barely-legal adults today.