On the one hand, it's a cool hack.
On the other hand, once someone starts abusing (and teaching others how to abuse) a system. The people in charge of the system have to take steps to protect the system (usually by limiting people's ability to use it). The net result is that we risk losing an extremely valuable discovery/communication tool.
On the gripping hand, life is all about accepting and adapting to change. We should accept that the tools available today might not be available tomorrow.
So I remain conflicted. Doing these sorts of searches by hand might result in a make-or-break connection for your business. Imho, by automating the technique we cross the line from using the tool to abusing the tool. And tools tend to break if you abuse them enough.
But, it's a cool hack.
Most of the top execs at my company (fortune 500) have internal only email addresses now, because of crap like this.
The hack is cool. Public directories of everyone's email address (which is the logical extension) - maybe not as cool.
Agree - I consider myself a social hacker... and I'm constantly tempted to show off my methods... but I try not to. A trick is more impressive if someone doesn't know they are being tricked.
And if everyone does it... it looses its magic.