Early yesterday Inside Facebook’s Adam Lovallo broke the news on Super Wall’s huge traffic drop from 2.1 million to 600,000 daily active users in a matter of only a few days. Tonight, RockYou founder and CTO Jia Shen confirms that the precipitous traffic drop was due to punitive action by Facebook – cutting off Super Wall’s access to viral communication channels – due to policy violations.

Speaking on the decision, Shen said in an email to Inside Facebook:

They turned it off for policy reasons that are slightly debatable. The stated reason is to improve content on the application by implementing the right tools to reduce undesirable content. There are really quite a few details, it doesn’t make sense to go into it since its very tit-for-tat.  Suffice it to say that we’re working to reduce undesirable content, and other applications are also being held or will be held to that standard.

The debatable aspect is that there are policies Facebook has issued, but there is always room for interpretation – and in light of current changes, the interpretation is a lot more stringent now in contrast to before.

Shen’s comments show Facebook’s increasingly strict approach to policy enforcement that even some of the largest developers don’t have full clarity on. Within the last two weeks, two other major applications – Top Friends and Social Me – have been suspended by Facebook for violations of privacy policies. We’ll have more as the story develops.