I'm aware of it, and hence use only things that are encrypted and not based in US. ProtonMail. VPNs that don't log. Telegram. Hell, even many agency sites are using hosting outside of US.
Yes, it is not clear where exactly the info was stored. But this story isn't exactly the only one of busted pii info making it to the feds hands.
I'm not sure for what kind of real damage you're asking evidence for. If your name is in the paper, for many mongers with SOs, aspiring careers and so forth, it's near damn game over. If not life breaking, it certainly is a life changing thing if you hide your mongering. Some executives were mentioned in that article. An arrest or even detainment is game over for many of them.
Now, yes, we don't know if any arrests were made via simply perusing pii info, but certainly it's not a good look for your info to be included anywhere near an illegal conspiracy. Even it's just being a consumer. I mean, ashley_madison pii leak ruined many a families. And they had many more reasons to protect the pii info.
If you're a big fish or a very high volume client, and especially if you're an insider promoting the girls, the feds might set their eyes on you during such a bust.
This isn't limited to orgs or agencies either, btw. I remember a thread in general discussion about a guy receiving a text/call from a provider whom he never contacted. And let's face it, as I always say, there's little integrity in this game. The POs and assistants don't exactly take the hippocratic oath to protecting your identity. There were cases of blackmail, bad actors using the info to harass (out) the BLd (and non-bld) persons and so forth.
Idk, I thought it'd be self-explanatory. You don't want to be on the ledger in a criminal investigation,especially if your input was significant. As we all know, people follow the money.