On: iOS 11.4 to Disable USB Port After 7 Days: What It...

[Someone]

2muchcoffeeman doesn’t say apps will migrate to other phones.

(S)he implies that your friend’s phone being compromised will leak data about you (email address, physical address, birth date, mails you sent, etc)

[ams6110 → Someone]

If you give your friend that data, it's out of your hands. If you don't want your email address or birthdate to be known, don't give it to anyone.

I pretty much opertate from the point of view that anything I send in an email or text is public, and temper what I write accordingly.