I have a folder /usr/bin/X11 that has MANY copies of itself as sub folders. I quit counting at 25, but it appears to go on forever.

All appear to be exact copies of /usr/bin.

1) How did they get there?
2) How can I get rid of them?
3) Can I just delete them, or will that wreck something?
4) If I do delete or otherwise lose them, how can I make sure they don't come back?
5) Any idea of what function they do/did?