My understanding is mostly the latter, but definitely also the former, but it's based off of "I worked there, but our customer list isn't public so I can't tell you who" type statements like you'll see elsewhere.
If I had to guess what it's been actually used for, I'd wager it's money laundering or counter-terrorism type stuff; it's fairly well suited to finding connections between people and entities given a large data-set, and unlike many ML models, it can tell you why it thinks someone is suspicious, which might be needed for justifying further investigation. This is a completely wild-ass guess though so take with a giant grain of salt.
If I had to guess what it's been actually used for, I'd wager it's money laundering or counter-terrorism type stuff; it's fairly well suited to finding connections between people and entities given a large data-set, and unlike many ML models, it can tell you why it thinks someone is suspicious, which might be needed for justifying further investigation. This is a completely wild-ass guess though so take with a giant grain of salt.