Apparently the paparazzi dude ran into Chris and Rhi Rhi getting out of their car in Tampa and when he tried to take their picture, Chris' security beat dat azz. Here's how TMZ is reporting it:

[Chris Brown's] security thought that Luis Santana, the cameraman, was attempting to enter the vehicle and went into action. For his part, Santana says that a window (not a door) was down and he tried to peek in and take a picture. He says Chris actually began chasing him, and that's when security took over.