NEW : Facebook says users in U.S. and U.K. can sign up . Comment: Mark Zuckerberg says the move may `` make a big difference over time '' More than 114,000 people in the U.S. are awaiting organ donations , government says .
NEW : Facebook says users in U.S. and U.K. can sign up . Facebook is allowing users to ID themselves as potential organ donors . Mark Zuckerberg says the move may `` make a big difference over time '' More than 114,000 people in the U.S. are awaiting organ donations , government says .