they WERE total scammers!!! i had a experience on guests who cancelled reservation after i sent them access code, and 2 hrs later they checked in by code, i sent them message to ask if they checked in then 1 hr later they run away, i reported to Airbnb but they did nothing, the guests slept on one of the bed and smoke drugs in the house, i am just feeling bad guests are getting more and more. they ask refund by making up stories, writing 1 star review by "cleaning"--because this is the most easy way to blackmail hosts. sometime they can say they see spiders, ants, ,,,, wowo, ,,,wish they were living in 5 stars house!!! this rating system makes guests getting worse and worse!