Its not theft its you paying for the service of the website. What la la land do you live in.
I suspect, your point is that If I only steal bikes of people eating in my restaurant and I ask for permission if they are seated(1), then this is not stealing. Because of the permission. I would argue. It is an incredible.... bad deal for the one eating in my restaurant and it seems to be in bad faith.
It is even another story, if it is the only restaurant or food source in town. Then it goes well beyond stealing…
(1) And I certainly use all (bad/dark) tricks you can think of to get their permission.