Extremely useful add-on not only for managing multiple profiles, but also for maintaining privacy by blocking certain websites from accessing global browser cookies. For instance, you can restrict all Google domains to their own container, that way Google will have restricted access to your personal information.

Works really well. You notice that information is not shared between containers.

This extension was great until the update that removed the option to do not force to open a site on some container, and normally run on default container again.

It's a great initiative, but it could use better integration, e.g. Sync settings per container, history based on container, etc.

Really like being able to access sites with different credentials concurrently. (Google is okay at letting you switch, but I have about 6 different Google accounts between personal, and different work roles.) Looking forward to the release that lets me use custom icons to help identify containers. Would also be great if I could click a bookmark folder and say "open all in container"

많은 웹사이트들이 제 쿠키 뿐만 아니라 딴 사이트 쿠키까지 들여다 보는 걸 아시는지요?
이 부가기능은 쿠키를 격리함으로써 쿠키를 통해 정보를 훔쳐가지 못하도록 해 줍니다.(특히 '구글' 같은 포털들을 따로 가둘 수 있어서 좋습니다.)
개인정보 도둑질 종합세트인 페이스북만 관리해 주는 Facebook Container 부가기능과 함께 쓰시면 좋습니다.(설정 필요 없음)

This is one of the best available features of Firefox. As I'm a Web developer, it makes my life much easier by allowing me to sign into multiple accounts with the same browser, all without increasing resource consumption beyond the level of a normal tab.

And as a user of online services, once all of my different user accounts are untangled, I know I'm less likely to be tracked by all of the services I use when I'm elsewhere on the internet.

Check it out! Firefox is a great browser, but I'd say this one feature on its own justifies trying Firefox, certainly so for anyone who tries to be conscious about their privacy on the web.

Useful add-on for privacy conscious people!
Firefox keeps on fighting a lone battle for years now!

Hoy la privacidad es importante. Gracias por ocuparse de ello.

Clean data only in selected Container is not possible but would be a very basic feature.