I had the same thing happen when I first started. Someone requested for two weeks (I had my max stay set to two weeks). In my case, the person was local to the area. I ran their name, and they had quite a long record related to alcohol/dui/forgery. I am guessing because it is quite hard to get a rental in our area, the person was trying to find a place to stay despite her record. I declined the guest. You can contact customer service for assistance if you would like, and you can message them and ask what they are doing for three weeks.