(RNS6-mar12) Clergy look on an iPad during mass at the St Peter’s basilica on March 12, 2013 at the Vatican. The cardinal electors who pick the next leader of 1.2 billion Catholics in a conclave in the Sistine Chapel will live inside the Vatican walls completely cut off from the outside world until they have made their choice. For use with RNS-CONCLAVE-ROME, transmitted on March 12, 2013, RNS photo by Andrea Sabbadini.