Airdrops you can just sign a message, doesn't risk the keys..
Hence why Theymos did not know about the airdropped coins claimed by Nastytreasurer until this thread popped up and LoyceV asked the question. So we as a community have no idea of how much exactly was claimed, when it or if it was sold and what happened with the funds - same with XLM, there were others but I generally ignored all those shitcoins (wish I hadn't now seeing some of the totals people talk about)