Facebook Inc (NASDAQ:FB) filed its 10-Q with the Securities and Exchange Commission after releasing its latest quarterly results, and one of the key takeaways that’s worth noting is the question of how many users the site really has. This is an issue that goes beyond company’s financial information and, like other parts of running the social network, enters into safety.

facebook fake users

Facebook estimates the number of fake accounts

AllFacebook’s David Cohen pointed these numbers out. The social network provides estimates of fake accounts on its 10-Q filing. It reports that at the end of 2012, it estimated that about 5 percent of its 1.15 billion monthly active users might actually be duplicate accounts. In addition, 1.3 percent of them might have been accounts that were not classified correctly by users, while .9 percent might actually have been entirely fake.

Just this week we heard of how much of a concern fake Facebook accounts are. The Australian site Perth Now reports on the sentencing of Anthony William Rogers, who will spend the next three years in prison. He’s a teacher who was found guilty of using a fake Facebook account to “friend” his students and then get them to take nude photos of themselves.

Rogers would apparently use his status as a teacher to tell the students in his class about the fake boy he created on Facebook. He would tell them that the boy was his friend’s son who would be moving to the school soon, so when he sent the students a friend request, they would approve it.

Facebook explains its estimates

In its SEC filing this week, Facebook Inc (NASDAQ:FB) noted that there are some challenges involved in estimating the number of fake accounts that exist on its network. In coming up with their estimates, the company’s workers took a sample of accounts and used some judgment in determining which of the four categories each account fell into: real, duplicate, misclassified or just plain fake.

The judgment they applied involved using basic common sense like examining names which appear to be fake or some other behavior the account exhibits that doesn’t look like authentic activity. As a result, there’s not really any way Facebook Inc (NASDAQ:FB) can tell how accurate its methods were. In the filing, the company said its estimates could change as it improves its methodology for spotting the fakes.

Facebook attempts to weed out the fakes

Over the past year, Facebook has been attempting to eliminate the fake accounts. Last August, it confirmed that there were about 83 million fake accounts. Then in September, it tried to remove fake “likes,” and there was a staggering number of them.