Earlier this year I was day hiking/testing some new stuff in a popular scenic area. During this time of the year, the sun set at 6pm. The entire trail is short, taking about 3 hours at a moderate pace (including a short break). As I was leaving, a group of 4 college aged guys were entering the area. They had no water, inadequate footwear, and it was 5:00. Hopefully good sense prevailed and they turned around before they were hiking in the pitch blackness of night, but if I know college bros, they totally went for it, dude!

June of last year I was in the Sipsey Wilderness in Alabama when I saw a family of 6. Mom, dad, and four kids all 12 or younger. Again with the no food, no water, inadequate footwear, and so on. They were seeking the Big Tree (Alabama's largest tree, I think) which is a 12 mile round trip hike. When I saw them a few hours later they where lost, and asked for directions out.

Seems to be a recurring theme, though these two examples stuck out in my head. I guess they really aren't hurting anyone but themselves.