Apple is taking its first steps to declaring jailbreaking an iPhone illegal. Essentially their argument is that jailbreaking violates the DMCA (Digital Millennium Copyright Act) due to the reverse-engineering aspect of jailbreaking. Let's sift through this, and establish what we mean by "jailbreak" and "illegal."
As the DMCA is written, Apple is probably right: jailbreaking, that is to say, to circumvent included hardware or software to use the device with apps outside the Apple iTunes universe would most likely be a violation. That doesn't mean it should be though. We're not talking about unlocking. Unlocking, or making your device work on networks it was not intended for is a different ball game. The main reason I can cut Apple some slack on unlocking is the fact that carriers are subsidizing the purchase in many markets. I don't think it is fair (which should be a measure of law, one would think) for AT&T to pay Apple for half the price of a phone for someone to then use that phone elsewhere. That's a discussion for another day.
Some people have floated the idea of a Mac App Store. A one-stop shop for applications for your Mac. Imagine if Apple did that, then only allowed you to buy apps through that store. And, if you bought apps elsewhere, not only would it be frowned upon, but you would be doing something illegal. That doesn't make much sense. Does anyone remember the great cell outage of 2005? You know, the one where the guy ran an unauthorized app on his Palm and the network came crashing down? No? That's because it didn't happen, and it won't happen, and if it could happen, it wouldn't be stopped by the app store. To hide behind this shield of keeping customers and the network safe, is ridiculous.
Innovation comes from open systems. A company basing its OS on UNIX should know that.
That's my opinion. What's yours? Let's have a lively dialog in the comments.