Startup Idea : Trip advisor for tenants

A website for tenants to review landlords - not just the other way round. Landlords always demand references for tenants, but there are at least as many crooked landlords as there are tenants. It would be great if there were a website where tenants could go and review their landlords. Commercially, this would also be very attractive, as good landlords and letting agencies would want to advertise there (just like trip advisor). It would also fulfill a social good by disgracing bad landlords.