Warning, Booking.com blocked negative reviews. I had a confirmed booking at a hotel in Thailand and arrived at the hotel to discover that the hotel did not have a room for me because they had decided to give it to someone else who arrived earlier than me. Naturally I was extremely upset. I complained to Booking.com (who essentially did nothing) and also left a negative review of the hotel on the Booking.com rating system. Booking.com blocked by review because it was negative. I contacted them to explain why I had left a negative review (basically because the hotel did not have a room for me as per my booking) but they still refused to allow my review to be seen on their site.
It seems an extremely unethical business that deliberately blocks negative reviews of the hotels they feature on their site even when the hotel's performance justifies a negative review. So at the end of the day, the hotels are Booking.com's customers while are the paying guests are not. Booking.com will protect their customer base but not the paying guest