A report released Thursday said 4.5 million smartphones were lost or stolen in the U.S. last year, up from 2.8 million in 2012.

Thefts were largely responsible for the increase in devices that were permanently separated from their owners, according to Consumer Reports’ annual State of the Net Survey. The organization said device thefts nearly doubled from 1.6 million in 2012 to 3.1 million in 2013.

The number of lost devices increased from 1.2 million in 2012 to 1.4 million. More than 3,100 adults in the U.S. participated in the survey, which follows a commitment by phone manufacturers and wireless carriers to begin including anti-theft tools on smartphones made after July 2015 for sale in the U.S.