[AgentConundrum]

I don't have Firefox on this computer, so I can't check on that, but you're definitely wrong about Chrome. If you click Edit blocking options and uncheck a tracker, it unblocks it globally.

I wasn't sure of this last night when I wrote the comment, but I just tried it out with Google Analytics (since it's pretty ubiquitous), and it wasn't only unblocked on that domain.

[thelibrarian]

I must be misremembering the behaviour in Chrome/Safari. I guess the site-specific whitelisting must be a relatively new feature of the Firefox version that has not been ported yet.