Speaking as someone who hasn't played Black Ops, if it's too easy for campers to have an advantage over run-and-gun players, the only thing that should be changed is the layout of the maps. More alternate routes, fewer wide-open zones, et cetera.
Or, they shouldn't do anything at all. People always go on and on about how CoD should be more realistic---well, real snipers don't quickscope. They hide somewhere far away, don't move, and area denial is usually their main goal.
It's never not been a legitimate strategy, but if people really feel a change has been made, change something a little less personal than score and damage penalties. That just pisses of the players who enjoy camping. Instead, focus on map design, which is a subtler change to game mechanics that doesn't feel like it's punishing the player.