Not that this is the same thing, but we picked signs all the time on my baseball team, and I do it for my softball players as well. I don't think of it as "cheating" for two reasons: 1) as far as softball goes, I'm trying to teach them how to get a competitive advantage and how to dominate the game in a mental aspect (in other words, turn on an inside fastball when you know it's coming); 2) that's what signs are for... as an
attempt to conceal messages from the other team. If they fail to do so, that's on them baby. My point of all that is that "two seconds" is plenty of time. The fan doesn't have to raise his arm and signal fingers or anything. There are multiple upon multiple ways of delivering signs.
Anyway, I think I said it in the old thread, but if signs are being picked beyond what the players can see, then I do think it's cheating. So if a fan is doing it, I don't see that as being "legitimate." I'm not saying the Blue Jays are doing it, though.