I chase my kids outside often.
And they do way too much computer stuff. For a while, the mindless games were getting to be too much. Including the supposedly educational ones. I got a home design program, and they spent weeks messing with that, creating the most bizarre houses the thing could handle. The last few days, they have been going nuts on The Sims. Which they are playing cooperatively, one at the keyboard and the rest watching and offering suggestions. At this point in the summer, the main activity is arguing, so this is a big improvement.
But when they can't get on the computer, and have the choice, they don't usualy go out and play, they watch TV.
The computer is not a bad thing. The not going out to play and not socializing is. And I suspect that in most households, the computer isn't cutting into going outside to play time, it's cutting into TV time. I don't have a problem with that.
I really don't think I have to chase them outside any more with the computer and the TV than I would with just the TV.
The one kid I do have a computer time problem with uses it almost exclusively for chat. He's an intensely social kid, can't stand being away from his friends.