I know they try to keep bad reviews off their site. A place in Vienna where I stayed was noisy, stank of stale cigarettes, and had no curtains. When I complained the owner offered 10% back if I left immediately. When I refused he called the police. AIRBNB cancelled it so I could not review it. Another place in Paris was even worse but I couldn't find anywhere else so I stuck it out for a week. All the reviews were glowing for this place but my review never made it on the site. Very suspicious.