Facebook reached a major milestone this month, with the number of active users hitting approximately 687 million.
According to statistics gathered by the Inside Facebook Gold data service, new users continued to sign up from countries considered "late" to the FB craze.
Although nearly 700 million is still a massive amount of people, overall growth has been lower for the site for the second month straight.
In fact, Facebook gained 11.8 million users over the month of May, down from 13.9 million in the month of April. Overall, the site grew by at least 20 million new users over the past 12 months, albeit not back-to-back growth per month.
So where and why did users drop off Facebook?
Well, Facebook lost nearly six million users in the United States, falling from 155.2 million in early May to 149.4 million by the end of May. Canadian usership also dropped from 16.6 million to 15.08 million over the past year.
Could the slowdown be a byproduct of a brewing backlash against Facebook over various privacy issues?
As you may recall, the popular social networking site recently received a storm of negative media attention over its facial recognition feature
The new feature - which allows users to tag their friends in photos based on facial features - has caused some serious outcry in both Europe and the United States. The problem is not so much the feature, but the fact that Facebook makes the feature default for all users, rather than giving them an "opt-in" choice.
Europe has not seen a significant decline in its user base, but the facial recognition feature only rolled out in the last week, giving Facebook ample time to feel the backlash. In the United States, the feature recognition feature was rolled out some months ago.
If the drop in users is not caused by privacy issues, perhaps it's just a standard wax and wane of the Facebook machine. Nearly 700 million active users is a serious feat, so perhaps it's to be expected that some will eventually choose to drop off the site.