The most drastic example I can think of was an unverified rumor that a certain company would "fake" log users in when presented with valid credentials from a client they considered suspicious. They would then monitor what the client did - from the client's point of view it successfully logged in and would begin normal operation. If server observed the device was acting "correctly" with the fake login token, they would fully log it in. If the client deviated from expected behavior, it would present false data to the client & ban the client based on a bunch of fancy fingerprinting.
Every once in awhile, someone will publish their methods/software; Salesforce and their SSL fingerprinting software comes to mind: https://github.com/salesforce/ja3
I don't do much of this sort of thing, but numerous things come to mind. Aim to identify and whitelist obviously human browsers, blacklist obviously robot browsers, and mildly inconvenience/challenge the rest.
For example, an obvious property of a real human browser is that it had been used to log in successfully in the past. Proving that is left as an exercise for the reader, though it inevitably requires some state/memory on the server side.
https://link.springer.com/chapter/10.1007%2F978-3-319-07536-...