Bitcoin's pseudonymous, not anonymous.

Since every Bitcoin transaction is public, it's harder for criminals to hide from law enforcement than you'd think.

Busting child porn rings is - unfortunately - not priority, you can dig up as many of them as you care for if you know where to look. But the authorities departments tasked with dealing with these assholes is quite limited and more reports do not lead to more indictments.

That is why you use monero if you don't want government to spy on your every purchase.