There's a guy on twitter who has posted a few "remuxes" of films that appear to be ENORMOUS files (>1Terrabytes, etc.) in formats I'm not familiar with:
He's been asked about what exactly these formats are, his process, what the source material is, but none of his answers make sense. There's no way he can genuinely get files this large from even a UHD (<100 G) and I know he's not scanning film elements, so I wonder what the hell is going on. He does post scores of other legitimate rips and scans in formats and sizes that makes mathematical sense.
I feel like that checks out for ProRes encodes, based on my own projects I've exported in that format — especially in such a wide color space (4444). Nonetheless, seems excessive and frankly ridiculous, especially given the insane price of physical storage these days.
Yeah, those sizes aren't surprising for ProRes encodes of a three-hour movie. ProRes masters do leak, but based on the "4K DCP" labels, I can only guess that this person is somehow getting their hands on unencrypted DCPs, then doing ProRes encodes for obsessives who will happily take bloated file sizes (the 4444 encode is probably twice as big as the DCP itself) if it gets them closer to the holy grail of perceived losslessness. But since there's software out there that could directly play back the raw DCP on a regular home computer, I'm not sure why they don't leak that.