Here my naughty nomination: not a backpacking activity, but I was mountain biking at my local stomping ground and I came flying around a corner only to be greeted by a woman using the bathroom in middle of the trail. She couldn't go a couple yards off trail behind a bush? This was in August when there were plenty of vegetation to squat behind...

Nomination for nice: A woman I met while backpacking the other day. She was older lady telling me stories of her youthful hiking and camping trips. It was some interesting and fun conversation. I was hiking alone talking to myself until I ran into her party.