Firefox 59, from the next version, will improve their privacy by cutting back details that websites can share about the last site visited. It will remove much of the information that is passed on by websites to endeavor an improved privacy for users of its private browsing mode. When clicked on a link in the browser to navigate a new site, the site we go on to visit receives the address of the other site that we have come from via a name ‘referrer value'. This helps the website understand where the users are coming from. Not only this can disclose data of the individual browsing it can also tell the site about the exact page that we are looking for when we click the link, said Mozilla. When requested for other details like ads or other social media snippets, browsers also send a referrer value because it tells the site about the exact page that we are visiting. Some sites record this referred data and some sell it to allow site visitors to be targeted with ads.
[mnky_related_posts num="2"] Sometimes those referred data can reveal out highly sensitive information. Thus to prevent this type of leakage of data Firefox 59, the private browsing option will remove path information from referrer values sent to third parties.
This change prevents site authors from accidentally leaking user data to third parties when their users choose private browsing mode" as remarked by Luke Crouch -Mozilla privacy engineer
The defaults referrer option could be changed by the users in Firefox. In conclusion, this will override the browser's default referrer policy and also the site author's referrer policy thus putting the first choice of the users.