[user22]

I think the test is pretty straight forward and is basically an issue of risk and is not really directly related to the internet.

If having anything to do with X creates the perception of Y being liable for any legal and civil improprieties, then Y will dissolve any of its relationships with X.

<my take> For the parler case, Amazon didn't want to be held responsible for hosting content that (maybe) caused the problems in that nations capital, and certainly doesn't want to be held responsible for any future content/actions.

I think this can be justified by preservation of shareholder value. </my take>