Expansion day hits.
Zero balance in your bank account. Maybe come up with a lore reason, maybe not, either way everyone has to rebuild their bankroll. Nothing allowed be on the AH within 48 hours of the wipe. All banks cleared of every stackable item, no food, no mats, no potions, maybe just a few "flavor" items saved by being flagged - Noggenfogger for example.
How would you react?
(Just throwing out fun hypotheticals here, this one I like because frankly many people feel "priced out" of raiding. Gems and enchants costing an arm and a leg on many servers.)