TripAdvisor has been ordered to rewrite some of its marketing claims by the UK's Advertising Standards Authority.
The ruling follows complaints by hotels that the site had said that its holiday reviews could be "trusted".
The ASA said it was concerned that consumers might be fooled by fraudulent posts since the entries could be made "without any form of verification".
TripAdvisor described the ruling as a "highly technical view" of "copy that was used in a limited capacity".
However, the watchdog said that the ruling served as a warning to all UK-focused sites with user-generated material.
If you've not been following this, TripAdvisor in the UK was on a recent charm offensive to win over 'trust.' When you think about it, it's the same for every site that has user-generated content, however, TripAdvisor can make a business, and 'fake' or non-objective reviews can often break a business.