3 stars because
- each time I go to fb, tab often not being put in a container
- having to set cookie policy each time
- having to login each visit

Using in conjunction with add-on Multi-Account Containers.
DO NOT add a fb container to Multi-Account Containers or it stops Fb Container add-on!

Again 3 years later: Today fb, insta and messenger are not in a container. I disabled and re-enable Fb Container add-on and it immediately contained the 3 tabs.