All players are entitled to equal information, because, as John Vorhaus succinctly put it, "They say that information is power; in poker, it's cash, just cash."
This basic idea is at the root of the universal rule, "Show one, show all." It means that if you voluntarily show your hole cards to one player, every other player at the table is entitled to see them, too. If you don't make this happen yourself, then any player can ask the dealer to expose them.
But there's a practical problem that I have run into more times than I can count: Asking the dealer to show them doesn't always work. My standard phrase is, "Show those, please." The problem is that a fair percentage of the time, the dealer doesn't hear this request. It gets lost among the other conversations going on, as well as the general background din of the casino.
An associated problem is that there is only a very narrow window of opportunity in which to make the request. The interval between a player flashing his cards to his neighbor and the dealer sweeping them into the muck (after which it's too late) is typically two seconds or so. That's not much time for me to see what has happened, decide that I want to see what was shown, speak up, and have the dealer recognize and respond to the request.
After having had my "show" request disregarded way too many times, I have come to saying it rather loudly. It is also necessarily somewhat rushed, because of the number of times that the dealer hears the request, but doesn't register and react to it before shoving the cards into the muck.
The result, though, is that I can't help sounding rather insistent, forceful, perhaps even desperate. Those tones are just the natural by-product of saying something fast and loudly, so as to get the dealer's attention. Since adopting this change of tone, I have frequently gotten surprised or even alarmed looks from dealers. They occasionally glare at me and say something like, "OK, calm down."
I know of no way to get the perfect modulation of voice that would be sufficiently loud, clear, and rapid to be sure to attract the dealer's timely attention without resulting in an impression that I am somehow excited or desperate about the matter. I rather doubt that it's possible to achieve the middle ground that avoids missing information opportunities but also never results in a raised eyebrow and a scowl from a dealer who doesn't understand my dilemma.
Yes, dealer, I know you don't like to be yelled at. But if I don't come close to yelling, you and your peers have a nasty habit of ignoring me. You and your ilk have driven me to being insistent.
The best solution just occurred to me the other day.
I have stated here several times before that I believe that the "Show one, show all" rule does not just convey a right to the other players, but confers on the player exposing his cards an affirmative ethical duty: If you show one person, you need to show everybody, rather than making somebody else ask and relying on the dealer to show. But few players do this consistently, unfortunately. I think this concept needs to be functionally incorporated into the rule.
If I ran a poker room, I would implement this rule: If the dealer sees a player sharing his hole cards with another player, then the dealer is required to do two things. First, expose those cards for the table, without waiting for anyone to request it. Second, tell the player in question that if he is going to show one person, he has to show everybody. That is, make it clear that the dealer taking this action is a backup plan, a remedial action for a player who failed to live up to his responsibility. Teach players that the "flash and muck" is unacceptable and will be treated as a violation of the house rules. You can get a warning the first time or two, because people need a chance to be told the rule and overcome their bad habits, but after that, failure to comply will be deemed deliberate, and escalating sanctions may come into play, as for all other recurrent violations of the rules of the game.
This rule is most important when a hand has gone to either showdown or a late-stage bet without a call. It is less important when the hand being shown is folded pre-flop, and the flash to a buddy is just a "Look what trash they're giving me" gesture. Still, in an effort to prevent future problems and instill the meaning of the rule, I would have dealers in that situation politely explain that the rule also pertains to that case, and ask the player not to continue showing his cards. If it persists, then the next time the dealer will need to keep those cards separate from the muck and show them after the action has concluded--and keep doing this as often as it occurs, until the player learns not to do it.
Of course, the dealer sometimes doesn't see the post-hand flash, because it tends to occur right when he or she is busiest with pushing the pot, moving the button, clearing the board, dropping the rake, etc. There's no perfect solution, as far as I can tell. In those instances, we'll just have to revert to what is now the standard method of having a player actively make the request.
But if dealers consistently did as I describe, and if this procedure were standardized throughout all poker rooms, I think that we would gradually see a change in player behavior toward what I think should be the norm: a player who wants to show his cards does so by tabling them face up, not by flashing them semi-secretively to one selected opponent.