We have monsoon seasons here in Arizona that have multiple lightning events. We install surge protection and ground rods at each camera location and at the head end. The surge protection we use are made by Polyphaser. We install a bnc surge at both ends as well as a surge protector at each power supply. The system has to be "bonded" so the lightning does not "see" the indifferance to ground. Another way to do it is to place ground rods at equal intervals around the building and bond the building to the rods. I would recommend doing both. But, at least do the camera system.