[chrbarrol]

It is true that hiding it for many years would make it less attractive for terrorists, however one could imagine another strategy where you wait 12 months before anonymously telling the authorities you did it, without telling them how. (While threatening to do it again)

Having some unknown person(s) spreading Prion diseases around that cannot be detected until way after it happens would be close to the perfect terrorist attack imo. You could probably keep the attack going for at least a year before authorities get their act together, all the while people would be scared shitless as it would be very hard to know how the original group got infected a year earlier if you choose the right product to contaminate. (Not even mentioning the difficulty finding who did the contamination even if the specific product is found)

[XorNot]

Authorities are really good at de-anonymizing anonymous messengers. Who have no incentive to spread an unverified rumor they can't prove.