I don't know if this is the case with the proarcade but i read a page with the warning of a vulnarabilty in highscores (in general), where people can alter the score if they know the way it is set to the database, for example
http://www.test.com/forum/proarcade....You&score=**** or something like that. I did'nt test this though and i hope this is a problem already solved or irrelevant.