Seems like you'd want to subpoena source code or gmail history or something like that. Not much interesting in an office these days.
Sabu was put under pressure by the FBI, they threatened to place his kids into foster care.
That was legal. Guess what, similar things would be legal in France.
We all forget that money is nice, but nation states have real power. Western liberal democracies just rarely use it.
The same way the president of the USA can order a Drone strike on a Taliban war lord, the president of France could order Musks plane to be escorted to Paris by 3 Fighter jets.
I mean, if you're a sole caretaker and you've been arrested for a crime, and the evidence looks like you'll go to prison, you're going to have to decide what to do with the care of your kids on your mind. I suppose that would pressure you to become an informant instead of taking a longer prison sentence, but there's pressure to do that anyway, like not wanting to be in prison for a long time.