Usually I take the phone off the hook when I'm online tutoring -- there's more than one reason for that, as people who know me know well.  But there I was talking to a student in Beijing... and with the phone ringing in a way that was hard to ignore.  It was a little after 8:00 -- prime time for sub-finding machines.  That's who it most likely is, I told myself, a machine.  It's no news from loved ones, nothing that could faze me emotionally; I'll pick it up -- easy peazy -- then I'll hang up on it, and resume tutoring.  "I usually take it off the hook," I was saying to my student as I lifted the phone. "Hello," I said into the receiver.  No machine was there to greet me.  I spoke again; I spoke several times before I heard the faint click that told me I was no longer connected.  
I resumed work with the phone off the hook and my mind on the phantom caller -- on people who go ring in the night, then aren't there.  Was someone fazed by my words to my student, deliberately unwilling to intrude  on my session with so much as a voice?  There were questions in my mind as I drifted off to sleep quite a few hours later, with the phone back on the hook, and two diphenhydramine in my system (a higher dose than I've been taking of late).  I felt better when the drowsiness wore off (today early afternoon).  The phone's been reassuringly  quiet.  It was probably not a crisis or calamity that prompted someone to call, but then slip away without a word of greeting.
I communicate with people on a daily basis from all over the world; I experience little if any anxiety because I don't love those people or fear losing them.  That seems so logical to me -- it's hard to imagine experiencing fear in connection with a person unless one is fearful of losing the person -- yet it's brought home to me again and again that that's a perspective that's not shared by a lot of people.   Now then, whatever the LinkWithin widget picks as 'related posts, I give also: Plase Don't Email the Drops.