Apparently, something called Project Upstream is sending random messages to two people and then hooking the two people up to instigate a conversation. Neither person knows that they ’sent’ a message first. Usually, (or, as in my case, always), the messages are ignored by both parties. After receiving a few of these, I Googled around and found only the nixiepixel article above, though she links to some other info as well.
(Via Greg’s new blog Crotchety Times.)