The Mozilla Foundation has decided to take action against sites that abuse the option to send pop-up alerts to users' devices, displaying subscription requests to all visitors.
Appeared some time ago as a feature to quickly inform users about publishing new content on their favorite sites, the pop-up alert system works even without the target site being opened in a navigation tab. Predictably, webmasters motivated to increase in any way the number of visitors view this function as a means of attracting some of the casual visitors back
From now on, Firefox users will be able to choose to accept notification messages only from sources on a list of sites that are trustworthy. Thus, requests for pop-up alerts will be automatically hidden from the first visit to a site with a reputable reputation
The new setting can be found under "Privacy & Security" in the configuration menu.