BRUSSELS -- Street artist Banksy has lost a legal battle with a a greeting card company along with a European Union trademark for one of his most iconic artworks.The cancellation division of the EU's intellectual property office said in a ruling this week that Banksy's trademark for “Flower Thrower” was filed in bad faith and declared it “invalid in its entirety.”Also known as “Love is in The Air," the graffiti artist created the work in Jerusalem in 2005.