I discovered that one of my reservations was booked through their grandmother's name. Also this person only lives about 30 minutes from my condo which just seems a little fishy to me. I have IB turned on so I cancelled the reservation and reported the user. Within 20 minutes she rebooked with IB under the exact same profile but had changed her picture to a dog. Her original picture and snooping on facebook is how I caught her. That and the fact that she wanted information emailed to her real name outside of Airbnb. I didn't think someone could book with you if you had cancelled and reported them. So I have a message out to Airbnb CS. Any other suggestions? I see red flags!
If you don't want further contact from a guest, you can block the guest so they can't contact you or make a booking. You can look at Airbnb Help Centre which details how you can do this.
You will need to give Airbnb a call and explain your concerns. Hopefully they can cancel the booking.