An international environmental campaigning group has had its advert turned down by the search engine Google because it criticises the ocean cruise industry.
Google refused Oceana's 'Stop Cruise Pollution' paid-for ad, which accuses Royal Caribbean Cruises and the cruise industry in general of damaging the oceans.
The charity claims there is nothing in Google's terms and conditions that could explain the rejection, except a catch-all clause in its editorial guidelines that entitles it to act to "maintain Google standards".
Oceana's own website, Stop CruisePollution.com, lists the public record of Royal Caribbean's run-ins with US authorities since 1993 - it has paid out millions of dollars in settlements for discharges at sea, and for falsifying records.
The organisation wants greater enforcement of environmental regulations to prevent cruise liners discharging oil, hazardous chemicals and waste at sea.
Google's vice-president of corporate marketing, Cindy McCaffrey, said the company "does not accept advertising if the ad or site advocates against other individuals, groups or organisations".