I once passed a clueless wonder yacking loudly on his cell phone while pulling two little kids behind in a carrier. He was completely oblivious to the traffic around him. I repeatedly called out, yelled is more like it, but he continued to hog the middle of the trail. As I finally passed him I said "nice" and he pulled his cell phone away from his face long enough to yell a stream of obscenities at me. What a great dad!