No. It hasn't been enabled by default in my experience. It isn't the exact same as the Safari technology. Firefox lets you block "3rd party cookies" or "all

No. It hasn't been enabled by default in my experience. It isn't the exact same as the Safari technology. Firefox lets you block "3rd party cookies" or "all cookies" from the privacy pane of preferences. I've always "set it and forget it". The assumption is that many tracking cookies will come from 3rd party websites.