Just read this. The full article is a very informative read, link below.
Most of the people who are educated about fluoride will avoid drinking municipal tap water that is fluoridated, and will use a reverse osmosis system in your home to rid your water of fluoride. However, there are many who simply don't have the resources or the know-how to protect themselves and their young children.
In November 2006, the American Dental Association (ADA) sent out an email to alert its members of their recommendation to parents to not use fluoridated tap water to make infant formula. A few days later, the CDC followed suit. But neither of them openly informed the public! So there are millions of parents out there using tap water to make up formula, oblivious of the fact that the agencies that promote fluoridation in this country have issued a specific warning against using fluoridated water for this purpose.
Not only that, but by fluoridating the municipal water supply, you doom many low-income families to fail to protect their young children from this dangerous drug, even if they have this information.