> No where else can you "get away with" saying something that you couldn't elsewhere, and suffer absolutely 0 consequences for voicing actually controversial opinions.

I'm not sure you fully understand the issue. 4chan is nothing special, let alone remarkable, with regards to "getting away with" saying something. It's just a popular spot and the only one you know. I assure you that there are a myriad of forums and chatrooms all around the web that have the same sort of contents and even worse, being exchanged. The key difference is that 4chan is the mainstream, generalist forum, and a huge one at that with millions of unique monthly visitors.

Claiming that 4chan is unique in it's content reads like claiming that Pepsi is a small unknown soda brand that is almost secret.