Law enforcement and homeland security personnel face an average of 55 daily encounters with "known or suspected terrorists" named on government watch lists, officials told Reuters.
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The figure -- which equals more than 20,000 contacts per year -- underscores the growing sweep of the watchlists, which have expanded significantly since a failed Christmas Day 2009 bombing attempt of a U.S. airliner. But officials note that very few of those daily contacts lead to arrests.