More than half of people online have uploaded photos to be shared with others, according to a study from the Pew Research Center for a report that hasn't yet been published. It was 55% in November, up from 46% in July 2008, Pew's studies found.

Previously, the Pew Internet Project hadn't studied photo sharing as closely as status updates and blogs, said Lee Rainie, the project's director.

"The photo piece of this is now rising in importance and volume, we think, so we're going to pay more attention to this in the future," Rainie said. "It's become such a central feature for social networking."

Pew is also considering the privacy implications. "As location awareness now comes in your pocket with that smartphone, it's very likely that there's more of that (GPS data) inadvertently passed along," Rainie said.

Read More