It's a fun group activity when you're bored. In high shcool we used to run through the local mall and have contests to see who could "shoplift" the largest and most impractical items. People are trained to watch out for shoppers pilfering merchandise, they generally don't know how to react when you take half the giant props from their display windows.
Its also a good way to furnish an otherwise empty apartment. Cable spool coffeetable anyone?