Every newspaper critic of restaurants approaches the online, man-in-the-street reviews found on food websites with caution. Not because they're often badly written, comically misspelt or pig-ignorant about cooking, but because they often seem strangely partisan.
Sometimes you suspect they must emanate from the restaurant itself, from the owner's wife or mother ("If you're visiting London and can only afford one nice restaurant, let this be IT!"), sometimes they appear to be the work of a sworn enemy or professional assassin ("The service was rude, we were kept waiting for hours, the sauce on the chicken was out of a bottle, I'm NEVER going back".)
TripAdvisor does its best to plead fair play in its assessments. They're prefaced on the website by the words "Reviews you can trust," and every one is followed by the rubric, "This review is the subjective opinion of a TripAdvisor member, and not of TripAdvisor LLC." None of which reassures you that you're reading the words of a wholly disinterested party.
So, it's no wonder that several hotels and restaurants which have been rubbished by anonymous reviewers on the TripAdvisor site are seeking some form of retaliation.
I'm afraid they're doomed to failure. Even if they discover that some adverse reviews have been posted by rival restaurants, it's hard to see what legal redress they're entitled to.
Restaurant critics will await the legal outcome with interest. And restaurateurs will devoutly wish that the culture of online praise or condemnation by complete strangers had never got started.