Mall Stopper
The act of when walking through the mall, the person directly in front of you abruptly stops, looks around for perhaps a certain store, and then changes direction. This can sometimes cause a collision with the mall stopper or at the very least cause you, the victim, to stop short as well. These people rarely apologize. 
"Last night I banged into a group of 4 mall stoppers and was nearly killed." 

"I can't believe I got mall stopped today by a group of mall walkers." 