Crave

(Credit: Dong Ngo/CNET)

Apple published Thursday a support article cautioning users about jailbreaking the iPhone (as well as other Apple handheld audio devices).

Unlike the company's recent filing to U.S. Copyright Office that suggested that jailbreaking the iPhone might pose a national threat and be the cause of AT&T's unreliable service, the article states that "customers who have installed software that makes these modifications have encountered numerous problems in the operation of their hacked iPhone."

This means that if you get your iPhone jailbroken, for example, you will cause yourself, not others, problems. This is such a relief for me.

The problems that Apple mentioned include:

• Device and application instability: Frequent and unexpected crashes of the device, crashes and freezes of built-in apps and third-party apps, and loss of data
• Unreliable voice and data: Dropped calls, slow or unreliable data connections, and delayed or inaccurate location data
• Disruption of services: Services such as Visual Voice mail, YouTube, Weather, Stocks as well as push-based third party applications have been disrupted or no longer work on the device
• Compromised security: Security compromises have been introduced by the modifications that could allow hackers to steal personal information, damage the device, attack the wireless network, or introduce malicious software or viruses
• Shortened battery life: The hacked software has caused an accelerated battery drain that shortens the operation of an iPhone or iPod Touch on a single battery charge
• Inability to apply future software updates: Some unauthorized modifications have caused damage to the iPhone OS that is not repairable
... Read more

I just got my new iPhone 3GS the other day and the first thing I did with it was get it jailbroken, just how I handled my iPhone 3G.

This time around, it was not really because I was in dire need of any extra functionality (the 3GS now can do video recording out of the box, which my 3G could only do when jailbroken). Most importantly, I wanted to feel like I could do anything with a device I paid almost $600 for (I couldn't wait until December to be qualified for the discount upgrade).

Cydia store for jailbroken iPhones, where developers can summit their applications without having to deal with Apple App Store's policies.

(Credit: Dong Ngo/CNET)

Little did I know what would constitute "anything" in this case.

Apparently, as Apple claimed via comments filed last week (PDF) I, and my newly freed phone, could be the culprit for AT&T network unreliability and even more seriously, when disgruntled, I could use it as a weapon of mass wireless disruption by taking down AT&T wireless towers. (OK, honestly this revelation makes me feel kind of powerful.)

First reported by Wired.com, Apple's comments explained that jailbreaking allows hackers to alter the phone's baseband processor (officially called the BBP chip), which is the chip that enables the phone to connect to cell towers.

(A personal note: The only purpose of altering of the chip, via software or the hard way, I've known of so far is to unlock the phone, which allows it to work with other carriers other than AT&T. Jailbreaking doesn't necessarily mean unlocking and therefore is very much risk-free.)

Apple stated in its filing that by changing the BBP's code, "More pernicious forms of activity may also be enabled. For example, a local or international hacker could potentially initiate commands (such as a denial-of-service attack) that could crash the tower software, rendering the tower entirely inoperable to process calls or transmit data. In short, taking control of the BBP software would be much the equivalent of getting inside the firewall of a corporate computer--to potentially catastrophic result."

Now this is scary because I've never thought the iPhone--being the "Jesus" phone as it is--would have that capability. I always thought that Apple has been trying to keep it locked simply so AT&T could offer it exclusively in the States, which has been possibly the most successful exclusive offer a wireless carrier has ever had; and so Apple could keep tight control over its App Store, which is also a huge success. How naive and non-vigilant of me!

Another somewhat less serious manifestation of jailbreaking the iPhone that Apple mentioned is the fact that when changing the BBP code, a hacker can also change the iPhone's unique Exclusive Chip Identification (ECID) and therefore enable phone calls to be made anonymously, which "would be desirable to drug dealers".

As for AT&T's service, Apple claims that jailbroken phone owners could be the cause of its reportedly problematic network. This is because these unsuspecting users "encounter functional problems with the phone that result from jailbreaking. Such users often call AT&T to report such problems, believing that they may be the result of problems on AT&T's network. AT&T is then forced to spend significant resources investigating and diagnosing the problems to determine whether, in fact, there is a problem with AT&T's network or service."

This seems to explain why my co-worker Eric Franklin always has a high drop-call rate and bad 3G performance on his never-been-unlocked iPhone 3G. And why my friend in New York who uses a locked AT&T's Samsung BlackJack also has problems with dropped calls. (None of us, by the way, has ever called in to report problems. We just suck it up and have faith that AT&T would someday improve its service.) Now it turns out to be all my fault. (I am sorry, guys.)

What makes me feel a little better for my wrongdoing with my iPhones, however, is the fact that the Electronic Frontier Foundation has asked regulators for the DMCA exemption (PDF) that would allow consumers to run any app on the phone, including those not authorized by Apple. This would basically legalize the jailbreaking practice of the iPhones.

And Apple's claims are its response to questions submitted by the U.S. Copyright Office, which is considering EFF's request.

Editor's note: due to some technical issue, comments left prior to 9 a.m. PDT Jul 30 were accidentally removed. We're sorry for the inconvenience.

Tuan Anh Do shows off an unlocked iPhone 3G at one of his cell phone repair shops in Hanoi.

(Credit: Dong Ngo/CBS Interactive)

Editor's note: CNET editor and Crave contributor Dong Ngo is spending the next month in his homeland of Vietnam, and plans to file occasional dispatches chronicling his impressions of how technology has permeated the culture there. Click here for more of Dong's stories from abroad.

HANOI, Vietnam--Every obstacle presents an opportunity. I saw this firsthand in Hanoi.

Tuan Anh's shop on Nguyen Du street.

(Credit: Dong Ngo/CBS Interactive)

The obstacle in question: the iPhone 3G. Since its launch, it has proven a much tougher nut to crack than the original iPhone. Without a viable software-based unlock solution, the only way to make the phone work with any GSM carrier has been the use of a proxy SIM. Put this piece of very thin circuitboard in the iPhone 3G atop the carrier's SIM, and you can make calls and text on a new network.

(I did experience some problems using the proxy SIM, including short battery life, instability, and, most seriously, incompatibility with iTunes.)

Unfortunately, the recently released 2.2 software update, for now, has made the iPhone 3G impossible to unlock--unless you happen to be in Hanoi. Here, I met a man who takes the job quite seriously and gets it done the hard way, literally.

His name is Tuan Anh Do, and he's a 29-year-old businessman who owns five cell phone repair shops. A big part of his business is servicing the iPhone and iPhone 3G, and that often involves getting those devices unlocked at the hardware level.

One of his shops is on Nguyen Du street, a relatively small, quiet block in Hanoi. It's located in a typically narrow four-story house, with one floor serving as a reception area, and another holding the accounting department. The top floor is the workshop, where the magic happens.

Here I witnessed a brand new iPhone 3G getting its hardware unlocked and was really impressed. This is how it happened.