(CNN) -- About one out of every four Facebook users lies on their profile, and not just to impress that guy or gal who wouldn't date them in high school.
Sometimes, it's about privacy.
That was one of the findings of a Consumer Reports investigation released this week.
Titled "Facebook & Your Privacy," the report focuses on the ways people use the social-networking site to share information, and what happens to that information after they do.
In a survey of 2,000 households, 25% of users said they falsified information in their profiles to protect their identity, Consumer Reports said. That's up from 10% in a similar survey two years ago.
The consumer-advocacy site attributed that rise to growing concerns about privacy.
Some advocates, the report noted, want a national privacy law that holds all companies to the same privacy standards and lets consumers tell companies not to track them online.
There are some limits to a person's ability to prevaricate on the site. Facebook has a real-name policy.
It requires a real e-mail address (yes, you can create a dummy account that you only use to sign up for websites, but it's still yours). And you can't join certain networks -- those for college students, for example -- without the right kind of address.
"One can almost be a totally different human on Facebook than in real life," wrote Rebecca Greenfield for The Atlantic. "But, one can never escape their true selves, with the few details Facebook does not allow its users to fudge."
Some users have been known to create profiles under false or incomplete names to hide from employers or job recruiters. Others list fake birthdays on the site to foil potential identity thieves.
There have been several high-profile cases of fake Facebook identities. The 2010 documentary film "Catfish" chronicled the story of a lonely Michigan woman who created a false Facebook identity to flirt online with a New York man.
Privacy, of course, isn't the only reason to skirt around the edges of the truth online. In January, ReadWriteWeb looked at some of the top reasons for faking a Facebook profile. Among them:
• People hide things about their identities that may be personally troubling or even dangerous if others knew.
• In cases when a person is known professionally by a different name than his or her real one.
• Just for laughs
Most folks, though, might not be fudging the facts.
A 2010 study of college students in the United States and Germany revealed that they typically presented accurate versions of their personalities on Facebook and a similar German site.
"Online social networks are so popular and so likely to reveal people's actual personalities because they allow for social interactions that feel real in many ways," said psychologist Mitja Back of Johannes Gutenberg University in Mainz, Germany, who published the report with colleagues in Psychological Science.