
Violent protests, in the form of arson, firebombing, and vandalism started in the early 1970's in the U.S. Then, as now, most of the violence appears to be the acts of religiously-motivated criminals acting alone. However, recent cases involving the assassination and attempted murder of abortion providers in both the U.S. and Canada have shown that perpetrators appear to be sheltered by a network of sympathizers.
In recent years, the term "anti-abortion" has been used to identify individuals and groups which employ violence and murder to attain their political ends. They are differentiated from the vastly larger "pro-life" movement which rejects violence against persons and property. Both the pro-life and anti-abortion movements are motivated by one concept: that human personhood begins at the instant of conception. From this principle, it naturally follows that a newly fertilized ovum, an embryo and a fetus are all human persons who should be granted the same rights, privileges and protections as a child or adult. Some view an abortion clinic as the ethical equivalent of a Nazi death camp.
The pro-choice movement generally teaches that the fetus becomes a human person later in gestation, when it loses its neck structures which resemble gill slits, when it loses its tail, when it begins to look human, is viable, is born, or at some other transition point between conception and birth. From this viewpoint, a woman's access to a safe and affordable early abortion is viewed as a human right