(Portland, OR) -- Airbnb says its initiative to stop parties at rental properties in the Portland area is working. Under the policy, guests who are younger than 25 without a history of positive reviews can't book entire homes in their local area. They can book private rooms in properties where the host lives on site. On the 4th of July, 550 bookings were denied, along with another 550 on Halloween and over 700 on New Year's Eve. Airbnb says the program has received positive reviews from hosts who own the properties.