"Still logs in and lurks" may just be a family member using the same computer. I do not know how exactly it works but I am permanently logged in to TMO from four different devices and never bother logging out which may give the impression that I am online even though I took a few very long breaks this summer.

In fact, even when I logged out, opening any post logged me back in without any action on my side. No username/password request or anything. Probably the cost of not using HTTPS for this website.