I would think that, as in anything, there needs to be at least some risk anaylsis done before jerking your knee.
The first question would be: Why would we be a target(Is there a credible risk)?
The second one would be: Is the cost of the measures worth the available reduction of the risk?
The third one, assuming that the first 2 required it, would be how do we mitigate the threat and continue to do business.
As an example, while the Unabomber was active, were measures taken? Some were, by entitites that presumed themselves to be a target, but by and large, he was not deemed a threat to the general population.
He did a lot more damage than this scare has so far, remember. The half-assed measures illustrated above are silly and will do no better than make someone feel proactive, and cost time and money.
FYI that surgical mask has pores on the scale of 1000 times the size of the lowest grade Anthrax spore.
