I don't think I'm overstating the difficulty. It's not because, once one guy has hacked the system he can sell his knowledge, that the system is easy to hack. I might have been able to figure out the Tinder distance hack, if I had any interest in coding on mobile phones, as well as a use for that particular app, but it would certainly have taken me a while. Joe Average is not going to do it.
As for your refinement of the category idea, I like your point. Indeed, there is no need to recalculate once the answer has been given. And good point as well that users should have some sort of control over whether they wish for that data to be available or not.
Biting the hand that feeds IT
