Cars give me very little trouble. Bicycles, though.. at least a couple times a week I nearly get killed by one.
At crosswalks, typically I'm in a crowd of people and drivers know better than to try to make a turn through the crowd. Cyclists, though, will blow through, even just flat running a red light, and seem to have blind trust they'll be able to avoid hitting anyone even at high speed. One recent example: a guy on a bike, coming off a downhill stretch and towing something behind him, ran a red while I was in a crosswalk, close enough that I literally had to jump back. He was doing easily 30mph, and I'd be dead or seriously injured if he'd hit me, but did he care? Nope, he had places to be!
Same thing happens with bikes zooming down the wheelchair ramps off the Caltrain platforms; there are signs telling cyclists to dismount and walk the bike, but they know nobody's going to enforce it on them.
The one and only time I've seen anything done was about three months ago when a bike, stuck in traffic on the street, suddenly hopped onto the sidewalk and scattered a bunch of pedestrians in doing so. Lucky for them and unlucky for the cyclist, he did it right in front of a motorcycle cop who ran over, grabbed him, and gave him an earful and a citation.
And don't even get me started on trying to get home the nights Critical Mass does its rides. I just leave early and hope to avoid them.