Where are the teeth in all this?
Who was it that said treaties were just "pieces of paper", to be torn up and thrown away when they'd run their course of usefulness? Hitler? Stalin? Bismarck?
Signing a pledge is so useless and ineffective as to be risible. Excuse me for a second while I laugh appropriately: ha ha ha ha ha ha, you've got to be kidding!
It's time to make explicit the linkage between executive pay and performance, by making organization heads *personally* liable for fuckups like this. If whoever's the head of the British Council had to pay, say, £200 per person whose data was lost, I think you'd soon see the British Council become a model for guarding data.
Since modern management methods include rejection of the premise that the buck stops on anybody's desk, least of all the head man's, it's time for teeth — and sharp ones! — to be embodied in the law. I will, however, be kind and generous and exempt from such draconian penalties pay up to the amount made by the lowest paid person in the organization.
The equation then becomes explicit: you want all that extra pay? Then do the work involved. You're not allowed to take credit for what goes right if you don't also accept responsibility for what goes wrong.
The idea has to be expunged from society that once you get the pay and perks of being in management you are free to do anything you damned well please. Quite the contrary: given the excessively high pay to executives, it's only reasonable to hold them to an equally excessive high standard of behavior.
PS: There's an objection to this scheme: it would encourage organizations to hide their malfeasances. Let's deal with that by increasing the fine ten-fold if there's evidence of hiding the facts.