[bilbo0s]

Only if you have it enabled.

But it wouldn't matter anyway, that other party in the communication could easily be somewhere with phone service but no data. Or someone in the group sms could be on a non apple device. Boom, Just like that, your communications have been sent to multiple carriers, including your own. Those carriers all pinky swear that they won't do anything bad with your sms though. So I suppose it's not that much of a problem. /s

Why would anyone use a public network to communicate in secret? If you have a need for stealth communication with another individual, (maybe you're a dissident or what have you), then you should use the proper techniques. And, yes, keep your data encrypted on your own iPhone. Do not back it up to iCloud. Or Amazon Photos. Or Backblaze. Or Dropbox. Or etc etc etc.

Oh, and never, ever, use Android. You likely don't have the technical know how to make a commercially available android device private.

[modeless]

> Only if you have it enabled.

No. If the other person has it enabled then your messages with them are stored by and readable by Apple no matter what your settings are.

[danuker]

> Only if you have it enabled.

What? If you back up your messages, don't you get the messages from your contacts? Why wouldn't they get yours?

[nichch]

> Only if you have it enabled.

This is untrue. I just restored an iCloud backup from my girlfriends account to an old iPhone. Our messages are included.

On my personal iCloud I have iMessage sync disabled and iCloud backups disabled. She has both enabled.

[Dah00n]

You would appear smarter if you dropped the fanboy-ism. Apple just as bad as Google, just in other ways.