A new survey from the Pew Research Center’s Internet & American Life Project reveals that more and more users in the United States are taking extended breaks, even "vacations," from the site.

According to Pew, 61 percent of current Facebook users admitted that "at one time or another in the past they have voluntarily taken a break from using Facebook for a period of several weeks or more." Explanations offered ranged from personal reasons such as "too much drama" to disagreements about changing privacy policies.

Regardless, the fact that more than half of its American user base has expressed needs to take such long breaks from using the site could be construed as a significant warning for Facebook.

What is probably most worrisome for Facebook is that one in four users plan to cut back their usage in 2013. (That will eventually translate into less traffic and less potential revenue for advertising, among other problems.)