What Facebook effort are you referring to?
And your point about it not being easy to tell is very true. This is why the thought about the virtual chaplain. People would hopefully carry enough real-world positive thoughts about chaplains into their virtual dealings to feel comfortable "talking" with an online chaplain. If a community had a designated chaplain, that person would be known to the other members of the community and anyone with issues would be encouraged to have confidential communication with that person. (Chaplains being licensed religious ministers are usually permitted by the law to keep the contents of conversations private ... except in a few very specific cases such as child abuse mandatory reporting situations.)
(I work at Facebook, but am not involved in this feature.)