It has nothing to do with any sort of feeling. Perhaps you should check your own mental state.

It is the same as any confidential data. Logs, readings from sensors, etc etc. If it's confidential and given to a 3rd party through a contract that doesn't mean that it's suddenly not confidential data for the rest of the world, even if the 3rd party leaks it.

And if you really have a lawyer trying to tell you that some, at best, extreme grey area, is fine to build a business on, I think you should find a new lawyer.