Hotel charged my card for a negative review. Booking.com did nothing.
Left a factual review with some negative aspects and the hotel billed my card with a message explicitly saying the charge was for a negative review. I took it up with my bank and they asked me to try and sort it our directly with the hotel first. Was dubious given the tone of their initial message, but I reminded them it was explicitly illegal in my country. Got the shock of my life when they refunded it.
I raised it twice with booking - they just ignored me, despite it explicitly violating their own terms and the law. I ended up just deleting all 10 years worth of reviews - if they aren't going to pull dodgy operators into line then I'm not willing to post reviews and contribute to their product.
After reading the horror stories here I may just stop using them all together!