I'm the author (Rob) of the original post that detailed the hack. A bunch of people have shared their updates with me, this is probably the most thorough yet.

I'm the author (Rob) of the original post that detailed the hack. A bunch of people have shared their updates with me, this is probably the most thorough yet. As I said when I first published the idea: please use it - and encourage others to use it - sensibly. I've not seen anyone abusing it so far. I've also found that when you 'discover' an email this way, you can typically Google it and find that it was already posted online somewhere. All in all, I'm glad people are innovating/iterating in this way. The people worried about 'spam' are really worrying about human nature, not technology.