NEW : Brown pleaded guilty last year to a felony charge of assaulting his then-girlfriend , pop star Rihanna . Publicist says shows cancelled over `` work visa '' issues . British officials say singer could pose a danger to UK citizens . Score: 6 Singer vents in Twitter messages ; one post says `` think ima go away ! ! ! ! ''
NEW : Publicist says shows cancelled over `` work visa '' issues . British officials say singer could pose a danger to UK citizens . Score: 6 Singer vents in Twitter messages ; one post says `` think ima go away ! ! ! ! ''