Apple keeping watch in iOS6

With the release of iOS6, Apple has returned to tracking the activites of it's users - and it's more difficult than before to opt out. While this is not intended to track you as a person, it does provide a unique ID that advertisers could track across sites, and use to learn your habits / behaviour through which they could make assumptions about who you are.

This could be used to further compromise your privacy if you used your phone at a place where you do authenticate - and that company also has access to the IFA data - which they could then use to learn other information about your habits.

For more information see here.