A while back, I posted a link to Let Me Google That For You in chat. It was picked up by the SO bot and I got banned for 30min. Not fun.
For future reference, is there a complete list of banned URLs available? Can this be added to the Chat FAQ?
I do not believe LMGTFY is banned in chat (or any other URL for that matter)
What probably happened was that someone flagged your post, and others flagged it as well to make it so that you were banned for 30 minutes.
If it was really "banned", then there would be a message stating so on chat.