When you’re browsing a website and the mouse cursor disappears, it might be a computer glitch — or it might be a deliberate test to find out who you are.
The way you press, scroll and type on a phone screen or keyboard can be as unique as your fingerprints or facial features. To fight fraud, a growing number of banks and merchants are tracking visitors’ physical movements as they use websites and apps.
https://www.nytimes.com/2018/08/13/business/behavioral-biometrics-banks-security.html