Figure a hacking group is a dozen people. That's ~8.3T per person to stash. I know plenty of folks with that kind of storage lying around, it doesn't seem insane that folks deep in infosec might have even more idle capacity.
Alternatively the first newegg hit for a 6T hard drive is $300 even. That's 17 of them so $5k plus shipping. Either add in a chassis with enough slots or enough smaller machines to distribute it so say double to $10k or less than $1k per person.
Or even lazier, to store all 100T on S3 for a month and pull it back out is ~$12k, again maybe plus a bit for an EC2 instance to do the shuffling. Again, ~$1k per person.
And of course if you're a hacking group the chances that you've got root on some small business servers scattered around the world are probably a bit better than zero.
Alternatively the first newegg hit for a 6T hard drive is $300 even. That's 17 of them so $5k plus shipping. Either add in a chassis with enough slots or enough smaller machines to distribute it so say double to $10k or less than $1k per person.
Or even lazier, to store all 100T on S3 for a month and pull it back out is ~$12k, again maybe plus a bit for an EC2 instance to do the shuffling. Again, ~$1k per person.
And of course if you're a hacking group the chances that you've got root on some small business servers scattered around the world are probably a bit better than zero.