Re: Files are not testimony
"As I understand it, police CAN seize a key upon your person with probable cause or pursuant to arrest. Why is a password any different from a physical key?"
They still can't use the key to enter your residence without a proper warrant. If they then find a safe and believe what they are looking for is contained within the safe, the original warrant must specify the safe or an additional warrant must be obtained to break into the safe. The difference with digital files are that the "safe" is really safe and may contain virtual thermite if you try to break into them.