I'm amazed at the number of people who equate breastfeeding mothers to men urinating in public, or to having sex in public. I've seen many people whose eating habits are so offensive, it would be nice if THEY were relegated to a private place in order to eat. Infants have a right to be fed when they are hungry, not when it's convenient for the the sensitivities of the rest of the world.
Let's look at this scenario: A woman with three children enters a restaurant. One child is 4, one is two, and the youngest is 3 weeks old. The father is serving a tour in Iraq so the mother is there alone with her three children. The waitress has just brought them their meals when the infant wakes up needing to be feed. How is the mother supposed to fulfill the needs of the infant if she can't feed her baby in the restaurant? Is she supposed to make the child wait while the rest finish their meal? Should she be forced to let her food get cold while she feeds her baby? What about her other children? Should they take their food into the bathroom so they can eat while mama feeds the baby?
If you find breastfeeding moms so offensive, I do not see any problem with excusing yourself to a private place while she takes care of the needs of her infant.