It's quite simple. Red means stop.
Let me prefix this comment with a disclaimer. I think the vast majority of cyclists tend to obey the rules of the road and demonstrate more concern for safety than a lot of drivers. This is definitely a case of a few rotten apples.
Having said that, if I have to dodge one more cyclist when I'm crossing on a green light at a proper crossing, I'm gonna get nasty. Obviously it doesn't cross some cyclists' minds that if they hit a pedestrian they're likely to end up scraping their face along the asphalt at a speed close to that at which they were travelling. Not to mention being kicked in the ribs by an irate and concussed pedestrian.
Maybe I should just get over it. I mean, if it was really important, it would probably be an offence*.
*This link opens an Adobe® PDF file.