So tired of this argument. The fact that Constitution does not prohibit them from doing it does not mean what they are doing is a good thing. "It's not unconstitutional" is a very low bar to clear, and clearing it doesn't mean you are doing everything right - it only means you are not directly violating the law, which you should be doing anyway. Nobody should get any praise for just not violating the law. And paranoid panicky reaction to literature that mentions sexual relationships is idiotic on the paypal side, is just wrong. I can see how dealing with certain kinds of shady sites in adult industry may be a burden, but dreamwidth is clearly not one of them, and it can be seen very easily if somebody at paypal was willing to spend 10 seconds on it. They just don't care.
> They can choose who to partner with by whatever metrics they want.
And, of course, this is not true for a long time - there's a number of non-discrimination and social-engineering regulations that substantially limit by which metrics you can choose your customers.