Haha, that failed spectacularly.

On stock Mac OS Safari (no plugins, no hardened config), I did what they asked and visited their site in incognito mode via a VPN. It gave me a different id, with a message gleefully announcing that "your ID is the same when you're in incognito mode!" It even showed me some supposed visit from a minute ago.

Jesus what a scam.

Hi, I work at Fingerprint. Our demo accuracy is actually much lower than in production. You're welcome to try it yourself for free: https://dashboard.fingerprint.com/signup