"Super user" is a new name coined to describe people who turn to the ER with astonishing frequency and at an astonishing cost to a health system already under siege. Researchers studying the crisis of America's overcrowded emergency rooms are beginning to focus on this largely undocumented phenomenon. The researchers say a seemingly intractable problem could be solved, in large part, by focusing on just the top 1% of emergency room users, who in Camden, NJ, alone cost $46 million over five years.