The Dollars Icon at the bottom of the main page is from the
dollars group on DeviantART. This is an actual Art that was created by it's leader, and they are furious that it was used without permission, so I urge you people to please take down the picture, and apologize to the dollars group on Deviantart.
The Dollars.
There are no restrictions or rules. You just have to say that you're a part of the Dollars.