It was never safe to travel to the US with your phone since the Patriot Act was in action, since they made it possible to search all your electronics and decide

It was never safe to travel to the US with your phone since the Patriot Act was in action, since they made it possible to search all your electronics and decide to refuse you entry for any reason. It's safer to come with a phone that's completely empty of private information, and re-image it remotely once reaching your destination.