Private browsing mode shield you only on local machine; your Internet service provider or your company can still know what your are browsing. Private-browsing still make sense from security point as explained below.
Here are good reason why you should use private-browsing mode
- Public computer usage - You are using a public computer and accessing your email/Facebook or bank accounts. Use private mode. No history, no passwords will be stored back for others to use.
- Temporary login to friends machine - Logging in from friends/colleagues machine to do a quick email/Facebook/etc. check. Leave no traces for friend to see.
- Login to bank website - Accessing bank account for any transaction? prefer private browsing as all plugins get auto-disabled and no unknown plugin records your keystrokes or monitors your web page and data posted to bank site.
- Privacy from google search - If you sign into chrome then all your search results are stored by google. If you wish to keep some privacy over what you search, use private browsing mode. Google or any other search engine will not be able to map search back to your account; of course you will be restricted to search non-adult content
- No auto-fill history - You don’t wish your username, search fields, or address get added to auto-fill history; private-browsing make sense.
- Privacy while accessing porn. Self explanatory as you don’t wish to leave everything in history.
Browser plugins and Private-Browsing mode - Browser plugins are apps that run as part of your browser to enhance your internet experience. Plugin as they are part of browser has access to each web page you browse, content of the page, and data you enter (email and passwords). With private browsing all plugin get auto-disabled and that’s great. You can enable a plugin selectively if you wish to. Ensure you enable only minimal set of plugins to keep risk low.
Starting browser in private-browsing mode by default - For any of the above security reasons or more, you can always start browser in Private-browsing mode by default. Here are ways to get browser auto-start in private mode - http://lifehacker.com/5530828/start-any-browser-in-private-browsing-mode
Incognito(Private-Browsing) in Chrome