I think there is something wrong with it from a variety of moral perspectives. A website such as this which only exists because of the freedoms of expression afforded to it, which courts participants almost entirely from societies in which they are afforded freedoms of self expression, has a moral obligation to treat those rights and freedoms with respect. I don't see any perspective in which interfering with a human being's right to self expression, barring extenuating circumstances, is anything but immoral -- especially when that expression is the foundation of your enterprise. Legally, of course, they're under no obligation to do anything they don't want to do. Still doesn't mean it's right for them to do so.