The onus to demonstrate benefit is on those who propose the action be taken. The onus to demonstrate downside is on those who object to the action being taken.It is about risk - and accountability. If you want to take a risky action you are accountable for your actions, or lack thereof. Positions that are allowed to take risks without accountability are generally in the public domain, rarely in private.Taking the flight prohibition as a case in point, what really happened was just that: a party with no accountability for their action imposed their will on others. I know this is in general a security practitioners nirvana: the business does what security tells them to. Utopia, isn’t it?The airlines wanted to take the risks, and they know which risks to take and which not. Benefits to them were clear, and so were the risks. Ask yourself: would any airline knowingly put their customers in danger? Airlines are as risk averse as they come - and they said it was safe to fly.Those passengers that wanted to take the risk and fly should be allowed to do so, leaving less people stranded. They are accountable for their actions, let them take the risks. Except that that flies in the face of overprotective, I mean risk averse, positions such as the ones shrdlu mentioned on her party invite list. :-)ADDENDUM: When you get the people that are paid to think in risk-averse frame to start thinking creatively and risk-proclive within their areas great things happen.