Yes. Facebook is much more intelligent right now. Last week I deployed an app for a client, it turned very viral, and facebooks bots stopped it in one hour.

The app only does this: you joiun, print on your wall, and must invite 3 friends to participe. That's all.

Anti spam bots suspended it.

So you can't run any viral app, except for the well known Zynga and all the rest of "parnters".