What proliferation? There have been a mere handful of cases of poisoned/tampered Halloween treats in the past 50 years. (If you believe Snopes, the most egregious one was done by a kid’s own father for insurance reasons.)
The only proliferation is that of stupid rumors and fears fanned by the media who’s out to make an easy buck out of totally anomalous stories.
Every time I hear this kind of fearmongering, it takes me one step closer to getting on a one-way flight and moving to a place that’s not polluted by the US/Anglo media.