Macbook was hacked over wifi?

So basically today at school there were some idiots hacking into other Macbooks (both Lion and Snow Leopard) over the schools WiFi network.

http://www.youtube.com/watch?v=qBiKGZxgPKg

That is the video of the hack in action, basically they are controlling your computer while you only see a padlock image.

My friend who was the one that got hacked (there was many more victims) never has told anyone his password ever, and once i turned my firewalls etc off, i already had these kids trying to get into mine, but fortunately i was able to stop them.

Just wondering if anyone knows what program this is and what this is through? (VNC, SSH etc...)

Thanks a lot.

-Luke