Don't feel bad about the "profiling". I think most people's reaction would be to defend their property first. At least you didn't try to "run them off" before finding out what was up!

Sometimes, all it takes is for SOMEBODY to get the ball rolling. I think its GREAT those young adults took the initiative, and even more happy to hear of others (including yourself) joining in on the clean-up effort!

It's an awesome experience for EVERYONE who gets involved!