It's an old request, they certainly know about it. But, apparently, they think it would be bad for their business to implement it. In the end, Facebook is not a public utility, it's a private website, belonging to Mark and shareholders. We're just allowed to use it, if we like it.
> But, apparently, they think it would be bad for their business to implement it.
While this is true, users have the power to change this dynamic. If the statement "Facebook promotes stalking behaviours by refusing to implement an invisible mode to help protect victims" (whether true or not) is accepted as common knowledge, for example, then that can change things.
It is accurate to say that they presumably must not have a business case, they're a private company and they can do what they like. This does not contradict others promoting a particular opinion in what they should do, because that has the power to create the business case for doing it.
