Hello! It is indeed safer in that what you do in a Private Firefox browsing session is not tied to any accounts that you may be logged in to in your Firefox browser. All cookies, site data, and history used is local to that session, and destroyed once the session is closed (when you hit the X on the private browser). However, your connection to any sites you visit is not anonymised, and ISPs/employers/sites that are connected to the browser may still gather information using this caveat. If you mean safer as in offering protection from viruses and malware, then no. Private browsing does just as much of a job protecting you as normal browsing does, and has no relation to antivirus/malware protection. It is purely for keeping the things you do within this mode private from others who may use the machine or account, as well as sites you visit and whatnot. If you wish to read further on how Private Browsing works, visit: http://mzl.la/1NATRAg