It's going to go into somebody's cloud whether you like it or not as soon as you send it to somebody else, unless the "private" flag is an end-to-end solution.

It's going to go into somebody's cloud whether you like it or not as soon as you send it to somebody else, unless the "private" flag is an end-to-end solution. If I send a private file or photo to someone, it should be encrypted with an ephemeral key which is not stored but sent to another device immediately, so that in rest it's not accessible. Then when the recipient receives the file, it is decrypted and placed immediately into their device's "private" space.