Depends who you ask and who's drinking. In general milk has very important vitamins that our body needs but in recent years more and more evidence shows that our body isn't that good at dealing with milk. It turns out that even people who aren't lactose resistant can have a certain sensitivity to milk and that too much milk can be bad for you as well.
Unless you are allergic to milk meaning you can't digest it, I say that everything should be done in moderation.