Maybe people are mixing it up with the american bb and that is why the tag is banned. then they should do it all bb# for all countries then. or maybe they don't want a brit big brother in another country? Conspiracies! why am i saying that i'm american and i like bb in usa.
Update: I tried #bb11uk still registers as a tag and #bb12usa
Link to prove it
http://twitter.com/Nintenfan3424