On: How can phone companies detect tethering?

[mullingitover]

This hasn't been true for a while. Anyone can build and install their own iPhone apps, the requirement to buy a developer license went away a while ago.

[vbezhenar → mullingitover]

I'm talking about OS. iPhone apps are extremely limited. For example you can't alter your network stack with iPhone app, AFAIK. Apple has so much control that you can't even install their own OS without their explicit permission, so you can't rollback to a previous version.

[mullingitover → vbezhenar]

Can't as in impossible to do, or aren't 'allowed' to? You can do a lot of things rolling your own local apss that would never pass App Store review.