Four Los Angeles middle schools scheduled to receive iPads have pulled out of the initial phase of the program. The Los Angeles Times says the schools want to hold off on providing students with the tablet computers at least until security and other issues are resolved. The schools: Palms, Webster, Muir and Revere. The rejection apparently is temporary — the schools still want the tablet computers — but their stance underscores ongoing problems faced by the school district as it pursues its goal of providing every student with a tablet over the next year.