Cached DNS Entries and Flash cookies
The big problems are the DNS cache and Flash cookies, neither of which are covered by browsers’ privacy controls. DNS, which is often described as the Internet equivalent of a phone book, translates Web site names (such as Switched.com) into IP addresses (e.g., 127.0.0.1). These IP addresses are saved locally to speed up access to those pages in the future. Private browsing modes don’t clear this cache, which means that somebody could tell what sites you’d been visiting just by looking at locally stored IP addresses, even if you’d cleared your browser history.
Cleaning these things up is as easy as typing “ipconfig /flushdns” into the command prompt (or ‘Run’ box, whichever you prefer), and deleting the contents of “%appdata%\Macromedia\Flash Player\#SharedObjects“.
The best solution is to install CCleaner and create your own batch file to run after your browsing session, to make sure your browser cache, Flash cookie cache, and DNS entries are cleaned out. Just create a new plain text file and save it as a .bat file (e.g.,
browserclean.bat), then add the following to the file, noting that the /AUTO switch tells CCleaner to run silently.
“C:\Program Files\CCleaner\CCleaner.exe” /AUTO
Once you’ve created the file and saved it into some useful location, you can create a shortcut on your desktop, quick launch bar, or pin it to your start menu.
Visit Lifehacker for a more in-depth look at how ‘private browsing’ modes fail.
Important! You have to remember that private mode does not hide your IP address, it only erases your browsing history!