In my defence a bloody great tank could come up behind me and unless it tapped me on the shoulder with its gun I wouldn't know it was there.
That is the other thing, just because you assume someone is being rude by not acknowledging you, try to remember the fact that they might not be able to hear you, I don't wear my hearing aids when running (sweaty ears bleuughh!!) so have to be more aware of what is going on around me.
It is not an issue but like i said please make it orginal. People with headphones make me cringe as losing your hearing although not one of the worst things that can happen, is in the least case scenario a bloody inconvienience.