In what could be bad news for Facebook, the world’s largest social media site, many users are planning to spend less time there in 2013.

Is the “Like” craze fading?

In a new report from the Pew Research Center’s Internet and American Life Project, 27 percent of users in the U.S. say they plan to cut back on Facebook time.

Only 3 percent plan to increase their time socializing.

The other 69 percent plan about the same amount of time.

Perhaps worst of all, younger users are the most likely to reduce Facebook time. According to Pew, 38 percent of users 18 to 29 plan to cut back.

The forecast is just part of an in-depth analysis of Facebook trends.

Another big finding is that 61 percent of Facebook users have taken a break from the site for weeks at a time. There is a myriad of reasons, whether they were weary from an onslaught of gossip, or for the more pious, the arrival of Lent.

Yet the use of Facebook remains pervasive in America.

Of the American adults who use the Internet, 67 percent are on Facebook, Pew found. That compares with 20 percent who use LinkedIn and 16 percent who are on Twitter.

But users do come and go, some temporarily, and some for good. Twenty percent of those with Internet access said they used the site at one point, but no longer do. By its own count, Facebook Inc. has 1.06 billion users worldwide who check in at least once a month. This includes millions of duplicate and fake accounts. More than 150 million users are in the U.S.

The largest slice of users, 20 percent, said that they were simply too busy with their own lives to follow the constant stream of status updates, George Takei quotes and baby photos.

Privacy and security concerns, which have received plenty of media coverage, were low on the list. Only 4 percent of people gave these reasons, combined with concerns about ads and spam, as their “Facebook vacation” motivation.

Lee Rainie, director of the Internet and American Life Project said privacy is more of a big policy question that people do not concern themselves with day-by-day. Rather, people are contemplating how they spend their time and allocate their attention.

“People are making interesting calibrations and recalibrations” about how they spend their time, and the worth of constantly staying connected to friends, family and others on line, Rainie said.

And while people do take Facebook breaks, Internet users are logging in more frequently than ever, the study found.

Among other interesting tidbits:

  • 59 percent of Facebook users said that the site is about as important to them as it was a year ago;
  • 12 percent said Facebook is more important to them than it was a year ago and 28 percent said it has become less important.
  • 8 percent says they took a break from Facebook because they were spending too much time using it.
  • 69 percent said they plan to spend the same amount of time on Facebook in the coming year. Twenty-seven percent plan to spend less time on the site and 3 percent, more time.

Responding to the report, Facebook (Nasdaq: FB) said that its growth and user engagement remains strong.

“As we announced last week, Facebook has grown daily active users across all regions, ending the year with more than 1 billion monthly active users, 618 million daily active users and 680 million people accessing Facebook from mobile devices,” according to a company statement. “Our announcement came on the heels of independent analyst reports which concluded that Facebook is the most downloaded mobile app in the U.S., and that time spent on Facebook accounts for over 20 percent of all time spent on mobile apps in the US.”

The Pew study of 1,006 U.S. adults was done in December. It has a margin of error of 3.6 percentage points.