> You don't need to have a monopoly to engage in anti-competitive behavior.
"Anti-competitive" behaviour is a much broader brush than antitrust, which has a reasonably specific meaning. Antitrust--in the US at least--relates to the Sherman Act [1] and the Clayton Antitrust Act [2].
Example applications:
> - price discrimination between different purchasers, if such discrimination tends to create a monopoly
> - exclusive dealing agreements
> - tying arrangements
> - mergers and acquisitions that substantially reduce market competition.
While such things are always open to interpretation by courts, it's important to consider their historical application [3]. Standard Oil and AT&T aren't anywhere in the same league as Apple.
It's worth noting that the intent of antitrust law and enforcement is to protect competition itself. AT&T is a good example because the barrier to entry for creating a telecommunications company was (and still is) so high.
Of course the solution was ludicrous and one that the US seems to have not learned its lessons about yet: it swapped one large monopoly for 7 regional monopolies. But I digress...
The Microsoft case is often brought up. It was a controversial case. At the time it virtually wasn't possible to have a (useful) PC (which accounted for >95% of the computer market at the time) without Windows. What's more, the nascent Web posed a strategic threat to Microsoft, one it sought to subvert by giving away IE for free and making it non-standards-compliant in an effort to tie users to IE and thus to Windows.
Now compare this to Apple. Apple holds no monopoly on phones. It doesn't require carriers to only sell its phones. Anyone content you sell choose to sell through the iTunes ecosystem you can sell elsewhere.
What people typically mean when they say "Apple should be investigated for antitrust" is "I really want an iPhone but I don't want one with Apple's restrictions so surely this should violate some kind of antitrust law right?"
No.
> Clearly Apple has a dominant position in online music sales
26.7% of music sales in 2010 [4]. Higher for online music sales I'm sure but is that a meaningful restriction? Antitrust isn't there to protect companies from competition. Any company can sell music. Amazon proves this. Apple doesn't require exclusivity.
The fact that to date any competition has been completely ineffective does not signal an antitrust violation in and of itself.
> Technological rate of change may be out pacing traditional regulatory adaptations.
There's no "may be" about it. And for this reason alone the DoJ will be reluctant to intervene (IMHO). For example, the Microsoft case was settled years after it had ceased to be relevant.
The market has a way of sorting these things out, at least as far as high-tech goes.
> It seems unlikely to me that Euro or US regulators will want to let a mobile computing platform become so vertically integrated that it controls all content, payments and communications arbitrarily with the only remedy being switching to a competing totally integrated platform.
No mobile platform has the sort of market share you're talking about to be relevant from an antitrust point of view.
I consider these vertical platforms to be a transitory problem and one that exists largely because the market is so new. These things will (IMHO) surprisingly quickly become commoditized.
It's for this same reason that I just don't really care about Facebook's apparent dominance of their space. Or at least I don't have the same sense of urgency about it that some seem to.
[1]: http://en.wikipedia.org/wiki/Sherman_Antitrust_Act
[2]: http://en.wikipedia.org/wiki/Clayton_Antitrust_Act
[3]: http://www.hg.org/article.asp?id=6025
[4]: http://www.tuaw.com/2010/05/24/itunes-share-of-the-us-music-...