Cookies are small text files that websites can store in your browser -- either first-party cookies from the operator of the website or third-party cookies that can come along for the ride from advertising and analytics firms. Mozilla is blocking those third-party cookies under a Firefox feature called enhanced tracking protection it announced in 2018.
Privacy problems like data breaches and Facebook's massive Cambridge Analytica scandal affected millions of people. Controlling browser cookies doesn't fix everything, but it can help with one part of the privacy problem by making it harder for companies to track you from one website to another.
"People feel increasingly vulnerable," Mozilla said in a blog post. "We believe that in order to truly protect people, we need to establish a new standard that puts people's privacy first."
The moves mark an effort by browser makers to become more assertive even when it means overruling the instructions coded into websites.
Years ago, advertising technology companies were instrumental in shooting down a technology called Do Not Track that could have offered consumers a way to explicitly tell websites they didn't want their web behavior monitored, but now browser makers are moving ahead on their own.......