[MertsA]

Well arguably yes. Currently there have been a few cases where judges decided to hold a defendant in contempt of court indefinitely because they claimed to not remember their encryption keys. At least in one of the cases the burden of proof might as well just be if the judge has a hunch.

Here's one notable article from almost a year ago but last I checked he's still being held in contempt. https://www.techdirt.com/articles/20160428/07395434297/so-mu...

It's one thing to demand that someone turns over their password but currently AFAIK there's no rigorous proof that the data in question is even encrypted or that the defendant had decrypted it in the past beyond "it was on his computer".