Sharing via Twitter what one over-hears out in public, in a coffee shop, at a restaurant, in line at the big box store, etc.
When your own daily activities are so boring and mundane that even you don't care enough to comment on them, and you resort to listening in on other peoples' daily lives.
See also eavesbooking, eaveslinking, eavesspacing, etc.
Mike (via blackberry) Says Alice, "I ordered some eucalyptus oil, for my cough." (Which was deep and growly.). "Yep, I've got it right here," replies "Nancy," "I was going to bring it to you this afternoon if I didn't see you this morning."
Karl (via Android): Stop with the eavestweeting and get a life.