We've improved Slashdot's video section; now you can view our video interviews, product close-ups and site visits with all the usual Slashdot options to comment, share, etc. No more walled garden! It's a work in progress -- we hope you'll check it out (Learn more about the recent updates).
What you said is different. It also depends on what the lost/found property was and the setting in which you find it. It's impossible to find out who that $10 bill in the street belongs to. The smartphone has information and contacts you can use to find the owner. You can even drop it off at the carriers store and ask them to contact the phones owner.
I don't think my neighbors in my apartment complex would like me banging on random walls to turn things on and off. Like wise I would get pretty mad if i heard someone just banging on the wall throughout the day.