Trademarked!

In August 2011 it was reported that a UK based company Keep Calm and Carry On Ltd had registered the slogan as a Community trade mark[11] and issued a take-down request against a seller of Keep Calm and Carry On products.[12] Questions have been raised whether the registration could be challenged as the slogan had been widely used before registration and is not recognisable as indicating trade origin.[13] An application has been submitted to cancel the trademark on the grounds that the words are too widely used for one person to own the exclusive rights.[14] The company is now trying to trademark globally in the United States [15] and Canada [16].

From Wikipedia