What is /b/?
I saw a few of these for the first time last night. I was cracking up.
/b/ is the asshole of the internet. I'm not exaggerating when I say 99.999% of internet jokes originate there. From Rick Rolling to LOLCats to Pedobear and everything in between. There's funny shit on there, but you have to sift through some gruesomely disturbing shit. If people think this site's fucked up, you have no idea until you see /b/. The only rule is no child pornography, but even that is violated from time to time. You also have to be able to read fluent l33t dork to even understand it. It's not a message board in the format you're used to message boards, either. It moves at the speed of light cause every dork in the world posts to it, and many of them spend every waking second of their lives on it. Threads disappear forever after moving past 11 pages, which happens in like 5 minutes of no responses.
Also of note, they're the "Anonymous" Internet "terrorist" group you hear about that crashed the Church of Scientology's web servers, etc.
I will link, but this comes with a strong view at own risk advisory warning. Also know that you will not get 90% of what you're reading until you've gone several times.
http://img.4chan.org/b/imgboard.html