The idea behind machine learning is that no single data point does the changing. It's about modelling you with a computer and determining if the model matches current models of fraudsters. If you do go directly to the payment page, you use tor for your browsing, you auto-delete cookies, and whatever else they check for, you become more clearly likely to be committing fraud. This does not mean, still, that you are committing fraud, only that you probably ought to be inquired about.

It's the same thing with, say, shoplifting. If you own a thrift store, and you see someone come in with a heavy coat, you might think nothing of it. But if that person acts suspiciously and holds his hands in his pockets, you may inquire as to whether that person is shoplifting. Of course, people do walk around suspiciously with hands in the pockets of big coats who are not shoplifting, but false positives like that are removed when the human element steps in at the last stage.