I read this article on bicycle theft today and I'm not really sure why but I found it fascinating. It is very well written but not really something that has enormous impact on my day-to-day life (although I have now shelved plans for expanding the looksoftware bicycle pilfering division :-)).
I did have my bicycle stolen when I was 12 so maybe I still haven't gotten over that. I doubt that is the cause though because my bike was dumped just around the corner (which taught me that there is some advantage having the worst bike on the block - mine only had one good pedal and a dodgy head stem so the thief clearly got frustrated very quickly). The upshot was that it only took about 30 minutes for my bike to be recovered.
I don't get to ride much these days, unfortunately. I used to ride a lot and it is still probably my favorite form of exercise but I have let it fall by the wayside and now favor more time-efficient exercise like running. One day I am going to splurge and get a really nice bike and start riding regularly again though.