Special counsel Robert Mueller's team is requesting that witnesses turn in their personal phones to inspect their encrypted messaging programs

Apparently, special counsel Robert Mueller's team is requesting that witnesses turn in their personal phones to inspect their encrypted messaging programs and potentially view conversations between associates linked to President Donald Trump. Since as early as April, Mueller's team has been asking witnesses in the Russia probe to turn over phones for agents to examine private conversations on WhatsApp, Confide, Signal and Dust, apparently.  Fearing a subpoena, the witnesses have complied with the request and have given over their phones. While it's unclear what Mueller has discovered, if anything, through this new request, investigators seem to be convinced that the apps could be a key to exposing conversations that weren't previously disclosed to them.