In theory. In practice there's a case where a defendant is being held in contempt (jailed) for years now, for refusing to provide her encryption passwords. At that point both the 5th and the idea of contempt are busted.
Link to story?
https://news.ycombinator.com/item?id=13629728
And he was freed after about 4 years.
https://arstechnica.com/tech-policy/2020/02/man-who-refused-...
> In practice there's a case where a defendant is being held in contempt (jailed) for years now
They are not still being held due to contempt, they were released. Now if he was convicted then thats different and the correct reason to be imprisoned.
> she
It was not a she.
The ruling showed that you can only be held for 18 months in the US for refusal. They would need to actually charge them with a crime if the government wanted more than that.
You know, I live in Poland, where up to 1989 when you were captured by police (which was called militia back then) they would beat the shit out of you or nag your family unless you incriminate yourself. And these were not democratic values. Basically the ruling system was authoritarian at that time. And I can see some similarities here between Poland pre 1989 and France nowadays.
-- EDIT --
Chat Control which was accepted by France is also really good connection to those times when your packages were being opened in the post office, if you were suspected by the one-party government. Also there was a time that all the phone calls were eavesdropped by security service.