https://developer.lyft.com/docs/lyft-developer-platform-term...
One section I'd draw particular attention to reads,
"You Will Not: a. use the Platform or Service in any manner that is competitive to Lyft or the Service, including in connection with any application, website or other product or service that also includes, features, endorses, or otherwise supports in any way a third party that provides services competitive to Lyft’s products and services, in our sole discretion; ..."
So if Uber profited from that misuse, why wouldn't Lyft have a case?