The Dollars are regarded as a colored gang that has no colors, but it’s actually just an online group. Anyone is allowed to join but only through invitations. Basically, you have to know someone from the Dollars to join the group. The Dollars group doesn’t have any motive or purpose, so you’re free to do whatever you want.
The Dollars were originally created by Ryugamine Mikado and his group of online friends, it was meant as a joke, but the online group kept on expanding. Due to the expansion of the Dollars group, the other founders left the group in fear of causing some trouble, only Mikado was left to manage the group, making him the leader of the Dollars. The gang became more popular and it kept on growing.
Trivia : Although the gang appears to be named after American currency, the name is actually derived from the Japanese term “dara dara,” roughly translating to “useless” and “not doing anything.” This is because the gang was created with no purpose in mind, the gang rarely ever involve themselves in any group activities, and its members are “colorless” and “invisible,” only identifying themselves as Dollars when specifically asked.
(Source: http://durarara.wikia.com/wiki/Dollars )
If you really want to know what the Dollars site looks like, you can do so here by clicking this link: http://www.dollars-bbs.org/
I think it’s amazing that something from the anime world also exists in the real world. If you want to know the password. You should watch Durarara!!, because I’m not telling it lol, or maybe I should tell it? Ok fine I’ll say it, the password is baccano, there you go.