Never started

Maybe you should join together with other rubes and hold a Rubicon.

Such a well-conceived feature could never possibly be abused for unintended purposes.

There are actually more operators than just JR and Keisei, but transferring between any of them is usually very quick and painless if you have any of the major transportation network cards in Japan, or associated NFC app. Only tourists actually buy tickets at the machines.

However, it does tend to cost more than sticking to one operator.