Right, I guess when you say "access" you mean "posting access"?
I was admittedly a little shocked when I realized that everything I do is PUBLIC PERMANENT RECORD.
https://hiveblocks.com/@logiczombie
It seems like someone could pretty easily make a "front end" that posted encrypted data to the blockchain and would only be decipherable with that specific app (HIVENCRYPT). That way people could make EXCLUSIVE (private) communities (well the content of posts would be "private" but all of their voting and transaction data would still be public).