Confiscating private land for building settlements (as opposed to security-related installations) is prohibited by the 4th Geneva Convention., and this is upheld by the Israeli Supreme Court. In a precedent-setting decision in 1979, the Court ordered the newly established settlement of Elon Moreh to be MOVED, because it was located on private Arab land. PM Menahem Begin was very unhappy, but complied. How nevertheless so much of the settlements area is private land is not clear. In many cases, some ideological ministers were acting against official government policies to support settlers. But this is not entirely bad, given the changing circumstances. Now that the evacuation of many settlements, at least those behind the "wall" is conceivable, appeals by Arab owners to the Supreme Court might push the process along.
Jewish teen sustains moderate wounds in stabbing in Jerusalem; assailant shot by police (Haaretz)