Guardian Unlimited reports that the European Commission has launched dawn reaids on pharma companies across Europe as part of its investigation into possible anticompetitive behaviour that could prevent new drugs and cheaper generic alternatives from entering the market. Companies raided on Tuesday included GlaxoSmithKline, AstraZeneca, Sanofi-Aventis, Pfizer and Merck, as well as their generic competitor Teva. The dawn raid tactic was deployed to prevent "highly confidential" information being "withheld, concealed or destroyed". It is thought that the investigation will focus on the use of patent law in order to prevent the market entry of new 'blockbuster' drugs. Trade marks, in contrast, by protecting goodwill of individual manufacturers, tend to differentiate their products and enhance competition.