Probably not the worst, but certainly memorable:
Suffolk in 2008, a nice stubble field away well from the road but on a bridleway, with straw bales in stacks. Leant the bike against a stack about 50m from the bridleway / track, set up the tarp around it and went to sleep. Middle of the night, sound of a slow-moving vehicle on the track, then repeated gunfire. I believe it is called 'lamping'. I was on the far side of a big straw stack and they would only be shooting in the beam of the headlights but I was still sh1t-scared. Seemed like they were there for hours but it was probably only 5 mins or so.
