I absolutely don't want built in features of my browser dependent on thirdparty services unless there is a standard way to attach it to alternatives.

There seems to be an about:config key for the backend, but I'm not sure if this is officially supported. The backend is open source [1].

[1] https://github.com/mozilla-services/pageshot

Actually, there’s even a setting in the settings menu of pageshot! http://i.imgur.com/NJI9FaN.png

I added some comments in another thread about local storage: https://news.ycombinator.com/item?id=12719270

That wouldn't use "the cloud"?

Another backdoor monitoring feature from Mozilla. Oh, and using it gives Mozilla the right to send you marketing emails. [1]

[1] https://testpilot.firefox.com/privacy

Actually, we've made email collection/messages entirely opt in (as the result of user feedback) :)

Edit: but we should update the privacy notice!

Notice how this only happens after they're caught by someone. Mozilla is supposed to have an internal privacy watchdog. Does it have any teeth?