The internet has not been anonymous in fact or theory for decades now, and if you think the government can't get your complete browsing history on a whim I'm guessing you haven't paid any attention to the news about NSA buying user data bundles from online brokers. That said, "muh freedoms" is hardly a quality argument in the face of the widely documented pervasive harms caused to children by exposure to social media. The logical extreme of your position would be to declare smoking in public a form of self-expression and then demand age limits be removed for the sale of tobacco products because First Amendment. :P
Ironically the "freedom crowd" are also statistically significantly more likely to get shot by their own toddlers accidentally so I'm not convinced they represent a pool of quality decision-making or grounded worldview. It's interesting how quickly any discussion of potential solutions to real-world problems gets chucked out the window the second someone says "freedom".
