A number of US companies have called on the federal court to declare discrimination based on sexual orientation illegal in an unusual move. Microsoft, Google, CBS and Viacom are among the 50 companies supporting a filing led by advocacy group Freedom For All Americans in the US court of appeals in Manhattan, according to Bloomberg. The move could increase the organisations’ vulnerability to employee lawsuits but, according to Anna Walker,Levi Strauss senior director for policy and advocacy, 'Laws that allow discrimination erode our ability to foster vibrant, competitive workforces, which halts growth, creativity, and innovation.'