Are you under the impression you're worth spying on? Why don't you just Ctrl-Shift-F12 or something to lock it when you actually want that?
I had bad experience with fingers as ID. Any spill on the scanner surface will disable it for days. And sometimes my prints change enough by being callous, or not fat enough or whatever. Just change. And then – no dice.
I am worth 'spying on' in my organization by the tens of non-workforce 'clients' that come into our office every day, including when I'm away from my machine. I don't 'just' Ctrl+Shift+F12 because I don't know when I might be called from one end of the office to another building, and I won't necessarily remember to stop and go lock my machine.
I don't drink by my laptop because that doesn't seem to be a worthwhile endeavor based on past experience. If my prints change then I can re-register them in about a minute or less. Enjoy your password/pin/whatever.
