Kuma said "I think the anti-abortion folks think it is wrong to *terminate* a life that already exists. I don't know too many people that use birth control and necessarily consider themselves pro-abortion as a result of that; rather, their pro-abortion views are contingent on the notion that it is alright for a woman to chose to abort an already existing pregnancy."
Some of the types of birth control still work if the egg is fertilized, and all types of birth control are designed to prevent life from coming into this world. Intent matters a great deal, and the intent to prevent life from forming results in many, many more lives from coming into this world than a later term abortion does. I'm not Catholic but I'll guess that is part of the reason for their stand on birth control, another part being their tendancy to display more intectual rigor than most faiths. I'm not going to judge anyone 'good' or 'bad' based upon being 'pro'life' or 'pro-choice', but I will ask some to get off of the soap box if they seem to display too much joy in throwing rocks at others on the issue, as they've made their choice on how to prevent life from coming into this world.