One of the bigger announcements coming out of Macworld Expo in San Francisco today is a new pricing structure for iTunes: Beginning today, songs on iTunes will be offered in three tiers: 69 cents, 99 cents and $1.29. After years of holding firmly to a 99 cent price point – to the consternation of many record companies, which wanted a bigger share of the royalty pie – Apple has re-negotiated the terms of its licensing deals. It won’t be long before the Beatles catalog becomes available via download.

But for our purposes, the security angle comes in Apple's announcement that it is banishing DRM (digital rights management) from its music library. Apple is saying the new offerings, without DRM, provide “higher-quality 256 kbps AAC encoding for audio quality virtually indistinguishable from the original recordings.”

DRM, you may remember, was the culprit in one of the first rootkit cases to make its way into mainstream media. In 2005, Sony installed DRM protection on several of its CDs to prevent consumers from making multiple copies of the digital music files. But there was a more nefarious component. Two software technologies embedded in the download - SunnComm's MediaMax and First4Internet's Extended Copy Protection – enabled Sony to gather information on customers listening to these CDs, and the software installed hidden files on users' computers that opened consumers to attacks from third parties.

Even though the CD packages were clearly marked with a DRM warning, consumers knew little about the technology, so went ahead and got their PCs infected.

Beyond the technical intrusion, the issue raised a number of ethical and privacy concerns. And the uproar, aided by an angered community formed via internet connection, took Sony to task. The company’s initial dismissive response only increased the volatility of the situation and managed to bring the issue into the spotlight. It was a PR nightmare for Sony, which eventually relented, attempted to fix the problem, settled court cases (with compensation for some victims), and ultimately, as had several other record labels, stopped using DRM on its CDs for the American market.

So, while it’s been a year since any major record label has placed DRM on its CDs, Apple’s announcement today – that music offered on iTunes will be DRM free – hopefully puts the issue to rest.

In his speech, Philip W. Schiller, Apple’s senior vice president of worldwide product marketing, filling in for Steve Jobs, said that Apple will offer eight million songs without DRM and add the store’s remaining two million songs by the end of the quarter.