Sean Avery of the New York Rangers leaves the ice after a fight with Michael Haley of the New York Islanders, not pictured, during third-period action at Nassau Coliseum in Uniondale, New York, Thursday, March 31, 2011. (Kevin P. Coughlin/Newsday/MCT) One thing is clear about twitter; it is not a useful conduit to express highly sensitive opinions about controversial social, political or racial debates. Period.Keep the 140 characters to describe things like what you ate for breakfast. Otherwise, you’ll end up like Damian Goddard.Damian Goddard, a freelance contractor hockey host, was fired from Sportsnet after sending an anti-gay marriage tweet....