I guess I should look into if it is legal or not in Madison, but we have a pretty strong Freecycle "program" going on here so it is fairly common to see people rifling thru stuff on the curb.
I like that, don't even look at them until you get them home.
I kind of overstated the not knowing until getting home - I instantly recognized the peaked fenders as being Raleigh Sports-esque and thus a worth-while to snag. We were just in and out quickly... I always get a paranoid/exhilirated feeling when I snag something out of the dumpster, so that motivates me to be quick.