I agree that the nature of the article is bad but still I would not be surprised to hear that Facebook is listening to phone conversations. That's why I don't use it. :P
If something like this is going on, only a few select employees know about it. Facebook is not dumb.
When it comes to "speaking out"... NSA started surveillance projects long before Edward Snowden was employed. There will always be people who will develop things like this and who will not speak out. It's just a matter of correctly selecting these few people.