Text (UG+errata): 3/3. ; Put ~this~ into play. Use this ability only if any opponent loses contact with his or her hand of cards and only if ~this~ is in your graveyard. [Oracle 2009/07/08]
To "lose contact" means to not be in direct physical contact with any of the cards in your hand. [QAS 1998/09/09] Being in contact with at least one card from your hand (if your hand has any cards) means you are still in contact.
If you've got no cards in your hand, you can't lose contact with it. [QAS 1998/09/09]
Deadhead says nothing about which part of your opponent must touch his hand of cards - any part will do. Clothes (including gloves) do not count as part of your opponent. [Barclay 1998/08/13]
All tournament formats have banned cards from Unglued.
