Think about what happens when you hit theverge.com: 40-odd requests sent sites you've never heard of. So-called internet connection records are a huge mess of noise even without considering obfuscation.

It is trivial for anyone to embed hidden iframes or send silent ajax requests to child abuse and terrorist forums without giving the visiter the slightest clue what's happening. In the case of iframes, there would probably be cached 'evidence' left on the target's pc. Try explaining that as your defence in court when you get set up by some script kiddie.