Originally Posted by SkyDog75

Not my bike, not my problem. ;-)

Seriously, though, on someone else's bike, I'm not going do anything about it unless it presents a functional problem. I might point it out and offer an opinion about how they might need to address the issue if/when it becomes a problem, but that's it.

My own bikes, on the other hand... Regular maintenance helps me minimize rust and a jug of Evapo-Rust helps me get rid of it when it crops up -- typically on small steel parts like stem bolts & chainring bolts.