As noted in a comment on the earlier post, Carrier IQ on iOS isn’t as bad as what’s on some Android phones. It’s only enabled if you said “yes” to allow diagnostics to be sent to Apple when you first setup your iPhone.
If you’d like to turn it off just to be on the extra safe side1, the toggle switch can be found by going to the Settings app on your iPhone and then General -> About -> Diagnostics & Usage.
- Or tinfoil hat side? ↩