About a week ago, Facebook was "upgraded" - don't know if it's a world wide issue - and the Facebook chat is always online. No matter I sign out. How can I disable / completely sign out of Facebook ...
When two or more people chat together, Seen by appears when one of the participants views the last message. It is nice to know your message has been viewed, but it is also an invasion of privacy. ...
I don't remember exactly how I got to it, but I opened a page (external possibly) that only showed the chat interface of facebook. It was quite similar to the gabtastik screenshot What I wanted ...