It's so interesting to now see this request from a viewpoint of a father whose sons would love to get athlete's autographs. A couple of decades ago I worked in professional baseball for eight years and one of my jobs was to get players to sign autographs for official team reasons. I would always see their player mail in the clubhouses and didn't really think twice about who was sending those requests (mostly kids, but you could also see when it came from more professional collectors.) Glad to see this method is still being used 20 years later in this day and age of instant feedback and social networking.