He has produced several studies that concluded Google favors its own services in results and has proposed possible regulatory remedies. (Edelman discloses that he consults for several Google competitors including Microsoft, the company's chief rival in search and a frequent critic. Edelman says his work for Microsoft has focused on Internet safety issues and auditing of Microsoft's online ad buying. Separately, acting as an attorney, Edelman previously represented a plaintiff suing Google about an unrelated search advertising trademark issue.)