WRT legality, fake testimonials are illegal in Europe (astroturfing and what have you), there was specific legislation to this effect called the Unfair Commercial Practices directive, eg http://www.theregister.co.uk/2009/12/08/eu_consumer_protecti... which in turn links to http://ec.europa.eu/consumers/rights/docs/Guidance_UCP_Direc... and http://www.out-law.com/default.aspx?page=9050.