Brendan Langley is seen in the video getting into a fight with a United Airlines employee. In the video clip the employee appears to slap him first. Apparently Langley was accused of loading his luggage on to a wheelchair to avoid the $5 luggage cart fee. Looks like the wheelchair behind them.
You just have to laugh at the :18 mark when Langley throws 5 right crosses and then acts outraged when the employee slaps him back.