This isn’t a crypto locker hack though where you can verify pretty immediately if they’re going to keep their word by them decrypting your data.
In this case the hackers actually physically have the data and are threatening to make it public if you don’t pay.
There’s no way to verify that they will never release it once you pay them. They could just sit on it for years after getting paid and then come back and say pay up again or they’ll release it.