Was at Beachy Head a few weeks ago, there are the Chaplins who drive and walk around, they are based by the pub, don't go in there for a last drink as they are trained to look out for those that may go over the edge, my advice is there is a small outcrop just up the path from the pub and the old WW2 lookout and was a quick way to go, just make sure they are no-where near and just run, i was able to stand on the outcrop without any attention, just don't look sad or down and they will hopefully leave you alone....