The event page says that you have to click a link and then press like on the promotion page. Now the link you click is a FB app. The app page says again that you’ll have to click the like button but before that you click ‘here’. And when you click there you’re subscribing the application. You’ll see the standard FB permission request page. It asks for personal info and permission to manage your events. But since you’ve been told that you’ll have to like their page (nice social engineering) you see this very important step as an annoyance and click the more prominent of the two buttons: Accept. This is when you spam all your friends. The app will send out an invite to all your friends that you have invited them to this ‘event’.

Some of my more tech savvy friends have recognized this and frightened their friends with deletion if they do this again. However these guys didn’t know that their friends weren’t the one spamming, they just giving access irresponsibly to an application.