So since the linking policy is now a bit more open, I can finally recommend to you guys this awesome Facebook group called Piece Out. And btw, it isn't only for Bionicle MOCs. We accept all types of LEGO building.
Many members here on BZP are in the group, so there might be some familiar faces there We also aren't asking you to reveal personal info, you can make a duplicate Facebook account and not have to reveal your real identity. As a few of our members already do.
It's 100% appropriate, no swearing or inappropriate content is allowed. Its a group for C&C, fun, and LEGO related activities in general. We have contests and projects too! (And a skype group).
We have 128 members at the moment, so it will always be lively! Hopefully some of you will take me up on my offer and join. =)