I personally think it would be far more interesting for spectators to be able to see both players hands, as well as be able to mouse over any facedown card to see what it is. This lets spectators see the decision making going on, instead of just the results. MTG videos usually let spectators see what is in players' hands. Poker shows do the same thing. OCTGN should follow this proven formula for entertainment value, even if it makes cheating possible via collaboration with a spectator.
League of legends fixed the possibility of collaboration by having spectators only be able to view the game state 5 minutes in the past. Something like this could be adopted.
Alternatively, chat could be disabled for spectators and hope that players and spectators don't have an alternate means to communicate.
This is a good idea. It's something we've been thinking about, but just haven't had time to implement yet.
yes, players should be allowed to enable visibility of their zones to spectators, however spectators shouldnt be able to see hidden cards/zones without the player's consent.