"Milk-sharing" is the term used to describe the process of donating or selling breast milk to other families. But, is it safe?Mothers who can't produce breast milk sometimes look to others for their child's early meals. Using breast milk to feed your newborn has been proven to be healthier than using formula. Some people will turn to the Internet to buy milk that they can't produce. But, certain breast milk could be doing more harm than good for your baby's health, according to a new study. Of 101 samples purchased anonymously, nearly three-quarters of the samples contained bacteria that could make a baby sick. Kristi Watterberg, MD, discusses the trend of sharing breast milk, including the potential dangers of buying it online.