Propaganda
Oracle Text
Creatures can't attack you unless their controller pays
for each creature they control that's attacking you.Card Rulings
10/4/2004 The payment is made during the declare attackers step at the same time you are declaring the attacker.
10/4/2004 If there is more than one Propaganda on the battlefield, the cost is cumulative.
10/4/2004 If there are multiple attacks in a turn, then you have to pay for each attack.
10/4/2004 Paying this cost is not an instant or any other kind of ability, it is an additional cost on the declaration of the attacker.
2/1/2007 In the Two-Headed Giant format, you still only have to pay once per creature.
2/1/2014 Unless some effect explicitly says otherwise, a creature that can’t attack you can still attack a planeswalker you control.
Anyway, this card is used in my Oloro, Ageless Ascetic EDH deck, along with Ghostly Prison, War Tax, Collective Restraint, Koskun Falls, Windborn Muse, Archangel of Tithes, Sphere of Safety, Norn's Annex, Isperia, Supreme Judge, Hissing Miasma, No Mercy, Moat, Reverence...
No one's attacking me. Ever.