"You may not enter this store"

I've been getting that a few times today while trying to enter mushies on my fm mule, was just wondering what causes it since i've never had that happen to me before, thanks.

You were banned... from that store

That or the person has you blacklisted.

Kicked out previously or blacklisted by the user.

Oh well, i see no reason for them to do so, just seemed fishy that i got that message on 5 different mushies, thanks for the answers.