Electronics are a big trigger for my kids. They want what they want when they want it, and I tend to have an iron fist about computer game-type stuff that triggers bad behavior. My kids can't play Wii at all this fall, and that's after they couldn't play it at all all summer. They play it once and get ROTTEN! Mouthy, mean to one another, angry, ignoring my rules, etc. When it happens now, I just cut them off. It solves a lot of problems. I get tired of it, especially since they are usually very well-behaved without the Wii.
I don't know if my experience there is at all relevant, since it sounds like the hitting came before the computer-related tantrum. The hitting seems to me to be a separate issue. But I'd see an outburst over the media issue from my kids, too. Not 45 minutes' worth, but a definite tantrum.
So sorry!
What are you thinking about it? What's your take?
