To find out what cell phone and what OS/browser one is using, typically one resorts to looking at the browser user-agent (check whats-my-user-agent) that the browser on the phone will send out in any web transaction, but that would require the user to do some browser activity on their phone. Note that hackers require this information to find out what viruses/malware they should throw at your phone.
Well, Apple with iOS 5 made their job a heck lot easier.
The hackers can now find that out by just sending a text message.
As you may have noticed, if you send text to anyone who has iPhone and is using iOS 5, the message automatically turns "blue" indicating the message was sent using Apple's internal servers and NOT through the service provider. It also indirectly (and may be inadvertently?) informs the sender that the recipient has an iPhone with iOS 5.
Do you think this information helps hackers? Do you think its a privacy concern? Or just a topic for someone to blog about :-)
I for one think its fodder for hackers.