I would imagine that it's possible that some of the people reading these comments might already know a lot more detail about Twitter/Facebook bots than this story goes into. Although you fine folks might remember me from a few other projects, I'm currently a Graphics Editor at The New York Times. We're actively curious and interested in pursuing lines of inquiry about this sort of behavior, and if any HN'ers have any…
You have an argument with someone on twitter and the next second 4 or 5 newly formed eggs with 1 follower apiece pile in to defend the other POV, sometimes without regard to civility.
It could be a coincidence.
Or it could be that the person you were debating let their ID out in another way.
Edit: Just to be clear, I was talking about the Freudian "Id" in all caps, used these days as a short-hand for a sort of unfiltered emotional inner child, and not "I.D." which is short for identification.