Ah, the old chestnut that is red light jumping.
Some people do it, others don't, some people have strict criteria for jumping, some will only do it on crossings, not junctions blah blah blah.
I have, in the past jumped them (mainly when no one was around at all, not a soul or car) but now I never do. My cycling style's changed a lot since I began two-wheeling last year and, for me, red light jumping's just not something I do. If someone else wants to it's their prerogative and as long as I don't get harassed for my decision I'll leave everyone else to theirs.
What did puzzle me though, was the absurd logic of a guy this morning. He kept getting in front of me, jumped one light, but not the next, weaved a lot and then, at a large junction I was totally confused. The light was red so he got off his bike and walked it straight across the junction. Not across the pedestrian crossings, he walked in the middle of the junction, in the middle of the road. Once he was across he got back on and pedalled off.
Luckily he crossed unscathed and managed to get a couple of minutes when the two roads with green lights were traffic free but WTF? Why not just pedal across if there were no cars? Why take an extra five minutes to cross by foot if you're not going to use the pedestrian crossings? Why make yourself look weird and eccentric? Maybe we'll never know.