Two Americans in three regularly use Facebook, the social networking site, says a new report by the Pew Research Center, a think-tank.
But a majority of users have taken breaks from the site, and young people are spending less time on it.
"Facebook sabbaticals"
The survey finds that 61% of Facebook users say they taken breaks from the site lasting up to several weeks.
The main reasons? It takes too much time to "prune" their profiles and the site seems less compelling.

The largest group (21%) said that their “Facebook vacation” was a result of being too busy with other demands or not having time to spend on the site.
Privacy and security issues didn't matter, though, to these people.
Young people have been there, done that
Facebook users between the ages of 18 and 29 said that the average time they spent on the site in a typical day had decreased in the last year.
Signs of burnout?
Most Facebook users have taken a break from the site at some point, the survey finds.
More than a quarter, or 28%, said Facebook has become less important to them than it was a year ago.
Among all Facebook users, only 12% said the site had become more important to them over the last year.
Pew used Princeton Survey Research Associates International to conduct phone interviews with a representative sample of 1,006 adults.
Social networking still the meta-trend
More than two-thirds of online adults use a social network of some kind, up from less than half of online adults in 2009, the study finds. So the trend in using these tools, especially on mobile devices, is staying strong.