~snip~
Is it possible that those 8 TB of data aren't actually data, but storage space - something similar to what happened in the case of CM? It might make sense that there is such a large amount of data, but why (and what) would a swap exchange store that takes up so much space?
Your guess is as good as mine. By the way, are we now certain of what specific data were kept by CM and seized by the authorities? Surely, however, the 7 TB wasn't just empty storage space. It must be a combination of logs, keys, other historical data, copies of the blockchain, and whatnot.
My theory about the value of the cryptocurrencies that were seized is that they may have been left with the intention of leaving the people who ran the whole thing alone. It's nothing new, in a way a kind of deal for the authorities to get money in exchange for giving up persecution - and besides, I think the guys behind this project made a lot more than those 30+ million euros.
We can only speculate, but CM has also left $47 million in addition to the 7 TB of data. So far, I haven't heard of Minh Nguyen arrested. This is like a replay, although not involving a mixer anymore but only one that's mislabeled as such.