Dwight Howard is bad at shooting free throws, one of the easiest shots in the game. Teams know this and some embrace it. They especially do so when time runs low and fouling him can pay off by extending the game and resulting in scoreless possessions or maybe only a single point. And so teams will chase him down to foul so that he gets put on the free-throw line until they go into the bonus.
Basically, they play tag.
Run away! - Monty Python and the Holy Grail (via danbiazoto)