In a previous life, I was once stranded for shabbas in some out-of-the-way hick town like Baltimore. After Friday night services, the Rabbi rose to the pulpit and announced that, effective that afternoon at 3 PM, the local butcher had been stripped of his kosher certification.
"But what about the meat we bought for Shabbas," exclaimed an old man in the front row.
"If you bought before 3 PM," replied the Rabbi (which, of course, everyone had) "the meat is kosher because until 3 PM the store was under our certification. We were on site. We had the keys to the freezer. We were supervising the deliveries. Even if the meat you bought before 3 PM is unadulterated horsemeat, you can still eat it. In fact, you should eat it. To do otherwise would undermine the chezkas kashrus."
Today Monsey is up to its armpits in boiling water because their local Wise Men didn't take elementary precautians. The faithful are being told to turn over their kitchers, and to cleanse their pots dishes and utensils (or to throw them out) because the store did not have a chezkas kashrus. The bad butcher was permitted to accept deliveries, and to slice and package meat with no outside supervision. He was trusted because of his hat, and his beard, and his payos.
I call rabinical malpractice, and I call on the men and women of Monsey to force their local Rabbis to answer for this oversight.