Mozilla has announced that Total Cookie Protection will be enabled by default for all users. Previously, this mode was enabled only when opening sites in private browsing mode and when selecting the strict mode for blocking unwanted content (strict).
The proposed method of protection involves the use of a separate isolated storage for Cookies for each site, which does not allow the use of Cookies to track movement between sites, since all Cookies set from third-party blocks loaded on the site (iframe, js, etc.) are tied to to the site from which these blocks were downloaded, and are not transmitted when these blocks are accessed from other sites.
As an exception, the possibility of cross-site cookie transfer is left for services not related to user tracking, for example, those used for single authentication. Information about blocked and allowed cross-site cookies is displayed in the menu displayed when you click on the shield symbol in the address bar.
Source: opennet.ru