stop sms messaging to iPhone programmatically

I want to confirm a feature, a client asks to me develop an app with a feature that it is able to stop sms messages to the phone for a certain period of time. I have done some research and found a link pasted below (and the screen shot of the page) in which the author of a renown iPhone App development book states it is not possible. What's your take on this?

http://img.skitch.com/20100816-tr4ceamtbjjfxqj9udd4tdpdwp.jpg

http://blogs.oreilly.com/digitalmedia/2008/02/when-it-comes-to-the.html

Core Telephony framework lets us 开发者_如何学运维get the notification when a call and sms is received but I couldn't find a way we can stop it.

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You probably can do it on a jailbroken device. You might be able to do it in a private framework (but it's pretty unlikely). It probably wouldn't be allowed in the App Store.

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You can't stop it, they were right.