Does iMessage consumes data?

Question

Since I did the upgrade to the iOS 5.0 I have noticed a tremendous data usage. Can anyone tell me if I message consumes data?

Answer 1

I'm on a 1GB data monthly plan for my iPhone 4 32GB and I rarely use more than 200MBs.  Imagine my surprise when, two days after installing IOS5, my ISP (Telstra Australia) texted me to say 80% of my 1GB plan had been used!  So, I immediately upgraded to a 2GB plan and relaxed.  Two more days later and another text from my ISP to say 80% of my new 2GB plan had been used.  It was then I turned to the Apple forums and discovered that the unaccountable high data usage issue after installing IOS5 was a common one.
My current position is that, 3 more days later, I now await yet another text from my ISP to inform me that I have used 80% of my new 5GB plan (this is getting expensive).
I have taken precautions to reduce data usage.  I have turned off Cellular Data and so my smartphone has become rather dumb.
There is something else that worries me. I have always had 'Don't Send' enabled in Settings>General>Diagnostics & Usage.  The message there reads 'data will not be sent to Apple.' However, when I checked this out I found that two transmissions had been made on two consecutive days before I turned off the Cellular Data.  I checked this out with a work colleague and they too found that their iPhone with IOS5 had been transmitting data despite 'Don't Send' being enabled.
Even stranger now, when I checked my iPhone this morning, the records of those two data transmissions were no longer there; they had been removed but not by me as this is not possible ... Twilight Zone stuff, maybe?
Lastly, the iPhone data counter during all of this zany data usage period has never risen above 500mb and yet when I talked to my ISP they were adamant that I had used copious GBs as recorded by them. I have no reason to doubt my ISP especially as unaccountable high data usage is being reported by thousands more iPhone users even as you read this message. So, is there a hidden program embedded in IOS5 that leaks information from the iPhone to Apple or some other organization without registering on the iPhone meter even? Twilight Zone again?
Interestingly, another friend uses an iPhone 4 16GB and his is unaffected by all this unaccountable high data usage.
More worryingly, Apple seems not to recognise the problem and because of that, there can be no solution other than turning the iPhone off. This is not a satisfactory performance from an expensive piece of technology made and sold by a company that claims to be leading innovation.
I believe Steve Jobs's biographer implied that Steve was the solo driver of Apple ... after he, the wheels shall start to come off ... it has begun.