There was a time when Lyft employees would call Uber cars, wait 2 minutes, then cancel the ride. This left riders driving around to pick up phantom rides, unable to make any money servicing legit customers.

If you're questioning whether this system should exist, it seems totally reasonable to build. The question is how aggressively do you use it to protect the company, and from which threats.

(And yes, Uber did that to Lyft too.)