Then if it is "possible" for even ONE competitor within the format to have access to "public" information that could give that competitor an edge within the format, the PTO should make every effort to ensure that ALL players within the format have that same access. I do not expect a PTO with decklists in their possession to hide those lists when one of their children comes near, but as soon as that child has seen even part of one list every other player should be afforded the same opportunity. Any person should be able to walk up to the TO's table, point at a competitor in the field, and ask for that player's decklist at any time during or after the tournament's conclusion (within reason, of course). The decklist in question should be produced promptly and courteously, and the person who requested it should be given time to copy the list by hand if they so desire.
I am in no way, shape, or form accusing anyone of any unscrupulous behavior, but I have to admit that the appearance is there if even ONE PTO with a child/friend/spouse who plays refuses to disclose a single decklist when asked.
Somehow I missed this response. In reply, I will NEVER hand over another players decklist to a player when they ask for it. Sorry, not going to happen! The ONLY people that will see that decklist will be myself or my judge(s) on the day of the event, for deck checking/registration purposes only!! I secure them after the event, my kids will not see them and they are kept for one year, unless PUI asks for them for some reason.
PTOs take their job very seriously. There is simply no reason for the decklists to be out in the open for ANYONE to see post event. The lists should be secured and separated immediately after the tourney. You seem to be feeding off the reply that a PTO "could" leak deck info to friends and/or family. Those same PTOs (leakers...if they exist) could also be double naught spys for the russians too! Bottom line, deck lists do not and will not be turned over to competitors, at least not on my watch. I dont live with the other 50 or so PTOs in the USA, so I cannot answer for all of them. I just know what I know from the ones I do come into contact with at Nats, Worlds, etc.
Keith