You have the tired, disgruntled, angry,

impatient shoppers who got up at 3am and didn't get to their store in time for the doorbusters at 4am. Their caffeine has long since worn off, so they are now going through withdrawal.

They realize this is their last chance for a doorbuster.
Mix that with people who got up at a civilized 10am, had their first coffee

and have an abundance of fresh energy, ready for their first doorbusters, and it could be a nightmare.