As I digested the information while my son was rapidly digesting the formula, I looked into his big, blue, innocent eyes so full of trust and wrenched the bottle from him.
Irrational but understandable thoughts flooded my mind - had I just fed my son deadly poison? Would he soon start frothing at the mouth and die?
Fortunately, my years as a journalist taught me that truth lies somewhere between the headlines designed to instil terror and the overly-optimistic reassurances of officialdom - in this case, the Government and police.
Perhaps I am naive - or else I am just too practical - but after a bit of tuning in, I decided to opt for calm over chaos, so I picked up my son's bottle and continued to feed him.
Surely if Big Brother from the Ministry of Truth says infant formula is safe, then it is, right?
Frighteningly, only time will tell. In the meantime, I carefully check my formula tins and carry on with baby business as usual.
But having looked at the conversation threads on various Facebook and news websites, it seems many mothers are not so pragmatic or trusting. Some are in a fearful lather and appear to be ignoring the real and proven risk of giving babies cow's milk instead of the (apparently) managed and unlikely risk of poisoned formula.
So, regardless of whether the person who threatened Fonterra meant to carry through on their blackmail, the reality is that already some babies are suffering as a result.
Those still getting formula now have dads going about town with milk moustaches as they execute their new role as food tasters.
The issue has made me wonder about the sort of person who would make such a threat. My conclusion is that they are one of two types: either profoundly stupid (for not anticipating the devastating economic and social impacts of their actions) or profoundly evil.
Evil is not a word to use lightly.
I take some comfort in the knowledge that the letter writer could not spell the name of New Zealand's third largest company so is even less likely to be able to bypass significant new security measures put in place to keep milk powder safe.
Even so, it is yet another example of the self-absorption dominating the 21st century.
In the same way that there is a new and ugly emergence of religious intolerance, there are people now who care little about the safety and rights of others as long as their own particular wants are met.
Someone out there clearly believes that the lives of introduced animals are more valuable than a human life and, regardless of whether they ever make good on their threat, that in itself is a tragedy.