[Friday, May 2nd]
Safari's private browsing feature causes the application to not store information about your browsing history. When private browsing is turned on, Safari stops tracking history, downloads, Forms AutoFill information, and searches. It's generally used on public or shared computers.
Apple's documentation on the feature states: "You can make sure you don?t leave your private information behind, without deleting other users? personal settings. Then when you turn off the private browsing feature, Safari resumes remembering your browsing history and other information."
However, as noted by MacFixIt reader Christian Buerli, private browsing does not preclude plug-ins from storing historical information.
For instance, even with private browsing on, the domain names of visited, Flash-enabled sites will be recorded to ~/Library/Preferences/Macromedia/Flash Player/#SharedObjects/.
As written by Christian:
"This can be easily tested by watching a video on youtube.com or other unsuspicious sites."
To be fair, this issue also affects other browsers. Using the "Clear Private Data" feature in Firefox, for example, will not delete the aforementioned historical information.
As such, if you'd like your browsing to be even more private, turn off plug-ins. In Safari, this can be accomplished by going to Safari > Preferences > Security and deselecting "Enable plug-ins."