Players hiding/showing card decks - bug or feature?

I use card decks from which players can draw for their spellbooks, and I just found out this last session that players can hide/show the decks for everyone. Is this how card decks are supposed to function?

Gozer the Gozerian said: I use card decks from which players can draw for their spellbooks, and I just found out this last session that players can hide/show the decks for everyone. Is this how card decks are supposed to function? I guess you could say the card decks are handled just like a "real-life" card deck at the table. "52 card pick-up" anyone? The bad, player's can show/hide deck for everyone. The good, all they can do is show/hide the deck for everyone... Cards in hand or "in play" stay. I suppose this is the way the decks are designed...?

Yes, it's not really a problem per se. Any player can always just re-show them, I was just curious if that's how it's supposed to work.