Do pro athletes have a responsibility to sign for their fans?

[chiefsngop]

My wife, 9 year old son, and I, went to the Chiefs OTA here in St. Joseph. After it was over the players hung around to sign autographs. The players finsished up and were heading out to leave, when my son started calling out to Dustin Colquit who was clear across the field heading up to the locker rooms, my son was holding a football for Dustin to sign.

Dustin turned and ran a good 80 yards back across the field to sign that one autograph for my son, what a great guy.