IRS says it will get a warrant before using cell-site simulators 

The U.S. Internal Revenue Service is drafting a policy to restrict the use without a warrant of cell-site simulator technology to snoop on the location and other information from mobile phones. 

Read more here:
http://www.pcworld.com/article/3011275/irs-says-it-will-get-a-warrant-before-using-cell-site-simulators.html