If its in your business' parking lot I would have turned it off. In a shady area I would have left it alone.

Standlights, on Hub Dynamo bike light setups, are like modern cars,
somewhat, you have a charged capacitor
to keep the light on, stopping at intersections.

If its obviously a battery light I'd turn it off, certainly..

I would turn it off.

Ha i left my light on again today, but someone nice turned my headlight off. THANK YOU

Hahaha, if you're touching somebody's bicycle and it is to turn off - you're doing it wrong! You must do it, ducimo... slowly!

If I could see how to turn it off from a distance, I would quickly walk over and turn it off. Some lights require a twist of that or a push of this and would be very conspicuous trying to turn it off. I would be very grateful if someone did that for me. I have three forward facing lights that are VERY bright and even though I use the low setting, leaving it in the high setting would burn the batteries in less than an hour (3 AAA). While I do get them at Costco (like 50 at a time), that is still saving me some. But if I saw someone getting close to my bike and standing there for a while, I would get a little anxious. I don't mind people getting near my bike (got some interesting stuff there!).

I have left my lights on a few times but they have all been at home. Like when I go inside with the intention of coming back out to do something, but never come back out. I have never left them on while somewhere else though, as I do a walk-around before I go to where I'm going (to make sure both the bags and bike are locked up.

I would turn it off. I sometimes leave my lights on briefly as I go inside to open another door to my indoor storage. It's along a well-trod but safe entrance to my work place. I have seen "cagers" try to turn them off but can't figure out how.

Speaking of touching bikes, not that I would do anything about it, but I sometimes squeeze the tires to see how well inflated they are.

I'd turn it off. I turn lights off on cars when I see it too, though these days mostly people lock their cars for some reason (I never lock mine, nor my bike for that matter).

Generally I only try to shut off a car's headlights if it's clear that they aren't going to do it on their own, but it's usually a moot point anyway because the car is almost always locked.

I would turn it off. And then adjust their brakes and overhaul the BB

Exactly, where do you stop!

I suspect you'd be gently caressing the top tube next particularly if it was a nice Italian road bike.

Not sure about that. Has been many a morning ive been late for the train, forgot everything but my backpack.
While touching a bike is a touchy issue, I think turning a light off is a nice courtesey. I would appreciate it. I would not appreciate fooling around with my bike.

I lock my car because I'm afraid people will mistake it for a convenient place to throw their candy bar wrappers.

lick, but don't touch

Yesterday was our clubs turn to sponsor our coffee stop for other licensed affiliated clubs as they passed through our town.. Hundreds of cyclists descent upon our club house like locusts.. We all touch each other's bikes but usually in their presence.. The touch of the day.. Some dude recently bought a $10 K all carbon bike. With top line, Campagnolo components....It was an Orbea I think. It weighed less than 10 lbs..It felt about as heavy as an envelope.
, It was such a sensual experience some specifics of the bike's make up overwhelmed the human psyche. The owner seemed impressed that a crowd of on-lookers could not get enough.

My light doesn't turn off. Really, it is a hub generator light and when I stop it stays on for about seven minutes and you can't turn it off even if you turn the light switch off. It is just draining a capacitor so it is no big deal but I wonder if others seeing my bike parked would think they need to turn it off.