Interflora, Inc. v Marks & Spencer:

the English High Court has decided to refer a number of questions to the European Court of Justice for a preliminary ruling in relation to the use of “Interflora” as a Google AdWord – the proposed reference further underlines the current uncertainty as to the effect of trade mark law on key word advertising, such as that offered by the Google Adword service and is one of several cases on this topic before different European courts.