To say that Facebook has to tread lightly around privacy issues is an understatement, especially with a targeted ad push underway. Rather than navigate that minefield once more, the social network hopes to skip it entirely by posting an overview of how the ad system tracks habits while retaining our anonymity. For the most part, Facebook walks the fine line carefully. Its Facebook Exchange auction system relies on a unique, untraceable browser ID to target ads to specific people without ever getting their identity; both a mechanism targeting ads beyond Facebook and a Datalogix deal to t
