[icebraining]

Consider: each time you introduce a new device that has local, physical access to the place your data lives

Right. So don't do that. Put it somewhere else, and configure the original device to push to it rather than give the new device access to the original. You can use a service that implements the S3 API, then you don't even need to install new stuff on the original, just configure an extra endpoint. Also, encrypt before pushing (that counts for S3 too).