Every time I've done a Black Friday, it's always been fairly quiet. One year, some guy tried to cut the line at Best Buy (which went past another store around the building to the back loading dock), but literally everybody made him go to the back. I was #8 or 9 in line that time. Another year, the type of people who typically cause problems in a public setting, were threatening people because they wanted $5 kid's PJs at Walmart. Police were called and those people were forced to behave.
I went to Best Buy last year on Thanksgiving around 7pm and grabbed a nice Dell laptop for $250 (half price) and everybody just stood in the line as it moved forward. You got to the counter with whatever you had off the shelf, told them if you wanted one of the cheap laptops, paid and left.