As I'm sure some level 200+'s would agree, it gets a tad bit annoying when people repetitively ask if they can join your your locked room. Because of this, there should be a new tag called the Do Not Disturb tag, where anybody who isn't on your friends list can't whisper the room master. This is a classic example of what happens to me on Sundays:
Random: Hey
Random: What's pass??
Me: I'm sectoring alone for a bit.
Random: Can I join?
Me: No.
Random: Why??
<I don't reply>
Random: Why?
Random: Hey you there?
So you see, this tag would come in VERY handy. Vote using the poll above!