This, according to an article from The Times Online:

Hotels, restaurants and online shops that post glowing reviews about themselves under false identities could face criminal prosecution under new rules that come into force next year.

Businesses which write fake blog entries or create whole wesbites purporting to be from customers will fall foul of a European directive banning them from “falsely representing oneself as a consumer”.

The new legislation takes effect December 31st, 2007 and will also apply to things like authors singing the praises of their own work on and tourist destinations that seek to raise poor ratings through fake postive reviews (which apparently is quite easy to do).