The copies must be found if they are in publicly viewable zones. Finding copies while searching private zones is optional.
2004-10-04
If the player has no cards in their hand, you still get to look through their deck, but you do not get to exile any cards.
2004-10-04
You only get to pick one card from the player’s hand.
2004-10-04
It exiles the chosen card plus all others in the hand, library, and graveyard. Some people thought the chosen card was not exiled due to some vague wording.
2004-10-04
Does not affect cards on the battlefield.
Target player reveals their hand, then you choose a card other than a basic land card from it. Search that player's graveyard, hand, and library for all cards with the same name as the chosen card and exile them. Then that player shuffles.