[Bring_Back_Shantz]

Originally Posted by CaramonLS

So what are the limits?

If I wipe my phone before I go through border the border, do they have the right to ask me to supply my itunes password so that my phone automatically downloads everything that I used to have back on to the device?

Is looking at downloaded email valid?

No, of course the don't, that's a pretty big leap, and a far cry from what is being tested by the case in the OP.
There is a big distiction between unlocking a device to see what data is physically on it, and getting passwords to see what data could be accessed remotely from it.
Likewise, there's a pretty big disticiton between a device that has illegal data on it, and a device that used to have illegal data on it.

Their job is to make sure you aren't actively carrying anything with you across the border that is illegal. A device that has been or could be used to do that is just fine as long as it's clean when you cross. A device that does have stuff on it? Not so much.