Powering off your phone or laptop erases the key that unlocks its encryption, and so protects against unwanted searches, EFF’s Will Greenberg told AP. “This is why a border agent can’t simply turn a device on to use a tool like Cellebrite.” https://apnews.com/article/internet-privacy-smartphones-travel-e0a3146ae7966ea0e4157dbfae1f6a81