Well! I personally have never breastfed my baby in public, and it was not a conscious decision but that the need never arose. And if at all I ever had to then being myself a shy person, I wouldn't have done it without covering my breast a bit, and not making it suffocating for my baby at the same time.
But, I guess it is a personal choice. If say, you are travelling in a metro, and your baby is hungry and you have to feed her, you must. And as long as you are comfortable feeding her without covering, I do not think it is anyone's business to interrupt. If you are comfortable, stare back at the women who are staring at you, or just ignore them with assertion.
Magbasa pa