Luckily nothing of the sort has happened. Yet with a global marketplace with millions of potential buyers for most any product, a tainted product could EASILY find its way into thousand of 10's of thousands of homes. If the taint is some sort of virus, it's not just possible, but likely that given enough lassaiz-faire attitudes from producers, that significant damage would ensue.

Malicious intent or not, negligence alone is enough.