a guest to threaten to write a negative review unless they receive a refund, upgrade or similar reward, in a form of "blackmail", which may be illegal in some countries. Venue operators are advised to flag such threats with TripAdvisor before the guest's review is filed. Fake reviews Fake reviews are common and has led to criticism of the company. In March 2014, Tripadvisor's Chinese site came under scrutiny when a user was found to have reviewed 51 Parisian restaurants in one month, while also reviewing 50 hotels in other countries. In November 2017, Oobah Butler, a journalist for Vice Media, claimed to have made money posting positive reviews for restaurants he never visited, in exchange for payment. In September 2019, consumer organisation Which? said Tripadvisor was still failing to stop fake reviews. Its survey of nearly 250,000 reviews for the ten top-ranked hotels in ten popular tourist destinations around the world found that one in seven had "blatant hallmarks" of fake positive reviews. Phantom establishments In May 2013, a fake restaurant was set up by a disgruntled businessman and reportedly had diners looking for the eatery in an alley filled with garbage cans. The fake listing went undetected on Tripadvisor for about two months. In November 2017, journalist Oobah Butler used fake reviews to boost a nonexistent restaurant named The Shed at Dulwich to the top of Tripadvisor rankings for restaurants in London. Reviews alleging crime In November 2017, Tripadvisor deleted reviews by two women who were allegedly raped at the Iberostar Paraiso Maya in Playa del Carmen in separate incidents 2010 and 2015, one of which involved a hotel security guard. The women said they received assurances from hotel staff that they would contact the authorities, but the staff failed to take any follow-up action. The women then posted advisories and warnings on Tripadvisor, but the reviews were deleted. The review of first victim, Kristie Love, was eventually reinstated, but the company claimed the review of the second victim, Jamie Valeri, was "hearsay" and it was not reinstated. The reports also highlighted at least 12 other such incidents at hotels and resorts across Mexico, including one of a 29-year-old man who was raped by a massage therapist at a resort in the same area, where reviewers had attempted to warn people through reviews on the company's site about criminal incidents that the resorts and local authorities had failed