HTTPS Everywhere

HTTPS
Everywhere is an extension that encrypts your communications with many
major websites, making your browsing more secure. Encrypt the web:
Install HTTPS Everywhere today.

HTTPS Everywhere is produced as a collaboration between The Tor Project
and the Electronic Frontier Foundation. Many sites on the web offer some
limited support for encryption over HTTPS, but make it difficult to
use. For instance, they may default to unencrypted HTTP, or fill
encrypted pages with links that go back to the unencrypted site. The
HTTPS Everywhere extension fixes these problems by using clever
technology to rewrite requests to these sites to HTTPS.