User Activity

Is there any way to stop someone from constantly changing ID's and wilfully disrupting your sales, because you gave them bad feedback or complained to Ebay about them or something like that?
I have a caravan listed on auction and have noted that I won't except bids from bidders with less than 10 positive feedback due to past problems with not getting paid. However there has been bidders with less than 10 positive feedback still making bi...