British government: I don't care how you get the little Zuckwit here, but get him here.
Drag the little cretin here in chains if you have to. Do a Mossad-esque operation like that perpetrated on Eichmann if that's the only way it can be done (not that I'm a fan of the OVOC but that particular operation was perfection).
But get the little asshole here.
Because if he sends a minion what you'll get is what happened with Hitler pre war - Kristalnacht - "Hitler wouldn't have allowed that, he must not have known about it" was what the (particularly gullible) people said, because all they saw were the minions fronting the policy. Uncle Adi kept very quiet about the whole situation for that very reason
What'll happen with Zuckerberg will be the same if he's not seen to be responsible - the gullible will say "the Zuckwit didn't know, he's a nice cuddly family man, he probably doesn't like smoking and gives people gifts if they stop"*. While your data is splurged everywhere and anywhere where someone will pay for it. Including individuals and organisations that you wouldn't want anywhere near your private information.
Personally Facebook should operate under the same rules as the NHS does if not stricter. The NHS can only lose your health data after all. Arsebook has access to a whole lot more information than that and can do a whole lot more damage if they choose to spaff it out to the wrong people.
The Zuckwit ABSOLUTELY HAS to be held responsible and be shown to be responsible - otherwise it'll happen again and again - more to the point if Facebook is seen to have gotten around it, then other companies will try the same thing - or heaven forfend the NHS (although in their case you just need to get a job as a BR carriage cleaner and it'll fall in your lap for free)
* Hitler stopped smoking personally somewhere between 1899 & 1918 depending on which story you believe. If a smoker on his staff stopped they'd get a gift of a solid gold fob watch from Mr H personally.
PS if you have a particularly annoying vegan or vegetarian in your life, and they're getting on your last nerve by spouting on as usual you might mention - mid rant - that Mr H was a vegetarian. That usually shuts them right up (or more accurately causes them to make similar noises to a Ford Cortina on a wet Monday morning whilst trying to recover the situation). Your colleagues/family/friends will thank you for it.