I'd agree - someone who was doctor shopping wouldn't go back to the same ER all the time. People who do this also will very often use different pharmacies as well. It's kind of awkward sometimes because I use ONE pharmacy to fill everything (that I don't get from an OP) and there's this one clerk who will look at the list of meds (the last 5 or 10 you've had print out on the receipt) and she always sniffs and says "Just ONE today?".