Facebook’s “You are already a member of this network” Bug (UPDATED)
UPDATE: As of at least 08/16/2011, neither of the methods listed in this blog post will allow you to remove yourself from a network (i.e., they no longer work).
Recently, I ran into a situation where I no longer wanted to be part of a specific network on Facebook due to privacy concerns, so I left it (or so I thought). A few days ago, I changed my mind and wanted to add myself back to that same network. Unfortunately, for me, even though Facebook did not list that network anywhere on my profile or in my account's settings, it still "thought" that I was still part of it, either because whoever wrote the function for a user to leave a network didn't do a good job at it or because the original function call when I initiated the request got interrupted somehow.
Facebook's "You are already a member of this network" Bug
Figuring this was a common bug, I did a search for the error message and found this. It wasn't much help, but at least I knew I wasn't alone. I tried contacting Facebook to look into the bug, but got nothing but an automated response. After looking around on and fiddling around with my account's settings pages, I figured there might be a way to force the site into making me leave the network a second time. Find out what I did after the break.
UPDATED: I've added step-by-step instructions on how to fix this with some additional screenshots. Check it out after the break.