>Would censorship legislation prevent you from doing so, if you really wanted to?

Would murder legislation prevent you from killing someone if you really wanted to? No? Then I guess there's no point in making murder illegal.

Legislation makes it clear what is sanctioned. It doesn't prevent crime. It defines crime.

>[...] unwanted information disclosure [...]

Legislation is how you say what information disclosure is unwanted. Without it, there is no basis for handling information disclosure at all.