Dear Guy walking your dog off leash while I run by,

I really don't doubt it when you say "You don't have to worry, he's too old to bother you". That's probably true, but he can still trip me up and I can still get hurt. You probably haven't thought about it the other way around, that I could hurt him if he gets in my way and I step on him, knock him aside, etc. Being on leash is for his safety, too. As I've heard it said "Unleashed is unloved". (Let's ignore for now the fact that we have a leash law in our town)