eBay has a new feature which all sellers have been looking forward to, I believe. Until this, we only have buyers reporting on a seller but now the tables are turned and sellers too could report a buyer. 

However, this just means that a buyer is being flagged and that particular account is being monitored for unreasonable pattern of purchase transactions. eBay may or may not update the seller on any action taken on that buyer, if any. 

In any case, if the report is found to carry weight, negative feedback on the seller by buyer would be removed, among other actions. That's one up for sellers, yay!