I don’t know if this has been talked about here already but I was listening to Fiverrcast Episode 25 “Protecting Your Online Business”… and they were discussing what you can do if you suspect a buyer of being a little on the shady side or a problem.
You can use Google as a tool to investigate to find out if any other sellers have had a problem with them by finding the buyers reviews and the sellers responses to them.
You just type into the search bar…
site: (space) www.fiverr (space) then username
I guess it’s not accurate all the time but might be useful.