This is not cool at all.
"This is the Cellebrite Cell Phone Extraction Device (UFED) and it can be used by police to extract your cell phone data during a routine traffic stop. The UFED comes in a rugged, road-ready case with all the connectors needed to grab info from almost every type of cell phone and portable GPS unit."
Legally, during traffic stops, officers need a warrant to search your cell phone; however, if you give them your phone voluntarily, they can use these tools to search it. Next time an officer asks you to give up your phone, ask to see a warrant first.
Taken from Translogic.