I installed KDE Neon on a t450s recently and the fingerprint reader was the only hardware that didn’t work out of the box. I had to install an extra package and add some lines to a pam config file.
I use it to log in, plus to auth for anything that requires root. I’m doing some coding so occasionally do something that requires sudo in a terminal. A prompt appears and asks me to swipe my finger. It’s very neat.
The fingerprint reader doesn't work though, not that I know what I would use one for.