Is your son ADD or ADHD? Or is it you? Because I have a younger brother who's 9, he acts like that if he wants to see a movie but someone else is using the DVD player, or when he has to get off the XBox. My little brother is bipolar, though. If your son is ADHD you might want to read about bipolar disorder, because some of the symptoms can be the same. Or it's possible he may have both (my aunt does). Of course, he could just be spoiled (NOT trying to offend you. MANY children are like that at that age, and they outgrow it). If these outbursts are normal, you really might want to find out things about bipolar disorder. If you want to talk about it email me at evilgenius2009@yahoo.com. I have a mom and brother who are bipolar, so I know some things about it.
But like I said, your son may just be having a tantrum that he'll outgrow. That can be normal. If you want some info on bipolar disorder here is a link: