Have Monsanto and the Biotech Industry Turned Natural Bt Pesticides into GMO “Super toxins”?

Is the supposed safety advantage of GMO crops over conventional chemical pesticides a mirage? According to biotech lore, the Bt pesticides introduced into many GMO food crops are natural proteins whose toxic activity extends only to narrow groups of insect species. Therefore, says the industry, these pesticides can all be safely eaten, e.g. by humans.