Additionally, the AntRank feature that uses this tracking can be disabled.
As the person who implemented Private Browsing describes:
Private Browsing aims to help you make sure that your web browsing activities don't leave any trace on your own computer. It is very important to note that Private Browsing is not a tool to keep you anonymous from websites or your ISP, or for example protect you from all kinds of spyware applications which use sophisticated techniques to intercept your online traffic. Private Browsing is only about making sure that Firefox doesn't store any data which can be used to trace your online activities, no more, no less.
Disclosure is good. Homogeneity and coercion are bad.
This is why the governments of the world need to implement do not track laws.
Not necessarily. There's no point in using regulation to preserve competition between buggy whip manufacturers. Creative destruction puts an end to many industries. And in some cases, its death throes can easily look like a market failure rather than market success.
In the end, who decides if it's a buggy whip industry? And who decides if a corporation is an oligopoly? Remember, it's likely that in any mature, regulated industry, the regulators are probably industry insiders themselves (see "Regulatory Capture", https://secure.wikimedia.org/wikipedia/en/wiki/Regulatory_ca... ).
Not all regulation is bad, just like not all effects of slavish adherence to free market ideals are good. The free market is good in aggregate, but there are many cases where government intervention is beneficial.
If Apple were caught doing this, there would be a hearing in front of congress.