The Tor Browser Bundle attempts to anonymize your Web browsing. It’s not perfect, and it does require that you modify your browsing habits. (You probably won’t be watching video while using the Tor browser, for example.)
It has been noted that people using the Tor Browser are noticed by the N.S.A. and sometimes targeted special illegal surveillance and sabotage. Some suggest that the N.S.A. has installed malware on the computers of people using Tor.