I'm more worried about a dog in NYC than a bird. I also used to leave my stretch cord on the rack, but now I have it attached to my pannier so it comes in with me.

:) Do you use it while on the bike? ;)

After reading the stories here, I guess I'm not going to leave the lights and mirrors on. I was not sure if there are thieves aiming at such things! I guess when I ride only during daytime I will not even bring the headlight--however there is always the possibility that something happens and you ended up coming home late in the evening. I really hate the fact that such a substantial part (including the cost!) of cycling has become anti-theft efforts :(

Well, of course. One bad back itch can ruin a ride!!! ;)

Several years ago someone took the front light bracket from my handlebar but left the light in the front basket. I leave my lights and computer on my bike because I typically can't be bothered.

But I hope somebody takes the crummy battery draining computer off my bike one day so I'll have a good reason to buy a nicer one.

I very rarely leave my bike for prolonged time, so I don't know when the screw and screw nut on my front basket became missing. It's impossible for the screw to fall on the floor even if riding on bumpy roads since the screw is long and tight. All other screws are intact. I can only conclude that someone had wanted to steal my basket (it's not quick release) during the very short time when I was away from my bike.

So they do steal anything, any time.