There are a few quizzes on the know-it-all section of Facebook where I have known all 10 answers straight away. I moved the mouse and I clicked on the answer as quickly as possible, but yet I still didn't get into the top 50 of people in that particular quiz. Do some people have a quicker method than using a conventional mouse to get a faster click on each answer?
Is this a Flash game by any chance?
Right click on it, does it mention Flash? If so, any high score table in Flash can be hacked. I suspect that is what these "high scorers" are doing.