Para o Firefox, use os dois links postados pelo TreyK. Para o Google Chrome, use Uma pequena privacidade
Prevents passing referrer to third parties, removes redirect trackers, resolves short URLs, and more.
This extension attempts to prevent passing referrer data through links to third parties by adding noreferrer to the rel attribute. It detects page changes, so that links will still get processed for pages like Google's Instant Search or infinitely scrolling pages like Twitter and Facebook.