Actually it's very simple to deal with.
Food that is subject to poisoning would be kept behind glass where people couldn't tamper with it and sold over a counter.
the people working the counters would be investigated. people working trucks, etc would be investigated.
It's be a pain, but it would be simple to implement and the economy wouldn't even hiccup.
The perps would be tracked down. (hell, we found some of the lockerbee bombers from a button on a jacket.)
Nice try, but technology has moved on from the 70's.
If it was a big scare, you can bet that the necessary $$ would be spent to take care of the problem.
You seem to be really preoccupied with killing innocent people for no reason.
rest assured, that if poisoning should start, you'd be one of the first people hunted down, even if you had nothing to do with it.
:devil: