It's not really effective because it takes years to manifest symptoms of prion disease. Terrorism usually has a message attached to it, and "you're gonna start dying in 10 years" is not conducive to messaging.

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)

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

living with knowing that i probably have 10 yrs before die in a gruesom neurodegeneration, knowing that if i interact much with our world that maybe i spread this to others, seriously terrifying, depressing, would induce misery.

I'm not disputing that. (also, prions aren't really human-to-human contagious, unless you're into eating your friends' brains or swapping syringes)

It would make it much easier to get away with than bombs and spread way more fear. If it would work (I have no idea) it would be a very intelligent choice of weapon.

In this case I guess the message targets people in other cities than the doomed one. "This could happen to your city too".

Wouldn't an entire city being sprayed with prions be a fairly apocalyptic event in and of itself? Those prions aren't going to go away, they'll get blown about and distributed by the millions of cars, buses, and trains going in and out of the city. What can you realistically do about that, go full Imperial Inquisition and raze the entire section of the country to the ground?

honestly, I doubt it. Prions do go away, exposure to oxidizing acids (nitrous, sulfuric), oxidizers like car exhaust ozone, sunlight probably damages them, random environmental proteases that are extremely hardy (because they are designed to work outside)... Also we don't really know of a way to make large volumes of prions; IIRC nobody has made a de novo infective prion, you could seed a folded prion protein to become infective prion using a biological source, but that level of biotech requires a significant lab with large-scale fermentation, or I suppose you could just grow flocks of sheep or cattle and harvest their brains, that would probably get noticed too.

We also don't really know what the population penetrance of prion is. It's possible, for something like british mad cow disease, basically everyone got exposed, but only some people got sick due to a random high infectious load, or a weakened capability of the body to clear the prion...

There are proteases in the body that are capable of clearing amyloid forms (insulin-degrading enzyme, e.g.) and it would be hard to believe that for a sufficiently small dose it wouldn't get cleared before it got to the brain.

strange, I just looked it up, but no one has investigated if increasing IDE expression in mice has a protective effect against prpSc infection (when the infection is not administered directly to the brain)... If there are any prion researchers here... Might be an interesting experiment.

you'd still have to wait a decade after the first attack to make threats on the second city.

I think reading about prions is the scary part, no need to wait for the deaths.

feel free to experiment with terrorism establishing credibility using a different psychological model. I, personally, won't.

Why even bother with terrorism? It sounds like a potentially gruesome and sadistic weapon with which to use against a particularly bitter foe- the terror is only incidental. Maybe it's akin to using a dirty bomb.