It is truly sad that we as host have to worry about scammers, they are out there, and please everyone take note of the suggestions made, in this posting about setting your cancellation policies. I agree many times you can rebook, sometimes you can not, depending on season, location, and your booking policies, plus I plan my time around hosting, so it is disappointing and some times costly when this happens.
THE OTHER SIDE OF THE COIN
I will tell you that as a host having to cancell a reservations, which was something I could not avoid because my long term guest with 4 children was unable to move on her date to be out and a wonderful guest had booked in advance, as soon as I knew she was not going to be out of the apartment I contacted the guest, and he was very cordial, and we agreed to the cancelation. I then cancelled AND WAS IMMEDIATELY THREATENED BY AIRBNB TO BE SUSPENDED, even though the guest and I had resolved the issue.
GO FIGURE! See my post about AIRBNB paying our sales tax.....UGH! Again NO WAY TO EVEN SEND AN EMAIL or SUGGESTION.