Are there any non-supply cards besides Black Market?
All cards not in the supply could include:


Cards in your hand
Cards in your opponents hand
Cards in play (including opponents)
Cards in your deck
Cards in your opponents deck
Cards in your discard pile
Cards in your opponents pile.
Cards in other locations (ie Village Mat)
etc.


Example Play from Intrigue cards:

Play a two Mining Villages, play two Bridges, play a Swindler.
Opponent turns over an Estate which is now valued at $0, replace opponent's Estate with a Curse.