I happened upon a site supposedly protecting consumers. It claims millions of verified reviews. Booking.com is there and its score is 1 out of 5. Almost all so called reviews give booking.com 1 star. The complaints are often outright lies eg. booking.com sends credit card details over unsecured connections to hosts. I never get credit card details from booking.com, let alone in non secure ways. There are also many complaints which are just plain preposterous like the family which booked 3 rooms in one place 6 months before their stay and they demanded to cancel a few days before the date. They then trashed booking.com and the host because they did not get a full refund. Full refund?! They should get nothing - imagine locking three rooms for 6 months then they cancel at the last minute.
We do sometimes complain about booking.com but after seeing these so called reviews (I have no idea how they are 'verified') I can see how horribly unreasonable and deceitful some guests can be.
The site is consumeraffairs dot com and sites like it are very unfair.