n. A person who obsessively and anonymously browses strangers' photos posted to online photo-sharing sites.
Other Forms
But perhaps most disturbing of all was the detection of a phenomenon known as "photolurking", which involves an obsession with browsing the online photo albums of complete strangers.

Since the popularity of photo-sharing sites exploded, the lives of snap-happy citizen journalists have been there for the lurking. And like the experience of Robin Williams' tragic photo developer in One Hour Photo, happy family photos offer the perfect escapism from an unpleasant reality. …

Perhaps the photolurkers aren't entirely to blame. Some photographers are posting their most private moments online, without any password protection, for all the world to see. It's not as if lurkers are hiding behind a bush taking pictures at your family gathering.
—“Online snappers told to beware 'photolurkers,” The Guardian, January 23, 2007
Web users known as "photolurkers" are flocking to picture album sites to snoop on complete strangers, according to researchers.

The growing phenomenon has been created by the boom in photologs which allow people to share pictures online with family and friends.

Anonymous visitors are also looking at the images in cyberspace but choose not to leave any messages behind in the optional message boards.
—Kim Pilling, “New obsessions as web users snoop on family albums,” Press Association Newsfile, January 22, 2007
2006 (earliest)
Then there are photolog sites like Flickr. While most of us would rather die than be caught surreptitiously browsing through someone else's photos, there need be no such qualms about the private pics people put up on these sites. Haliyana Khalid and Alan Dix at Lancaster University in the UK have studied this new practice of "photolurking". Most people they interviewed who used Flickr and similar sites spent time each day browsing albums owned by people they had never met. They do this for emotional kicks, Khalid and Dix suggest: flicking through someone else's wedding photos, for example, allows people to daydream about their own nuptials.
—Richard Fisher, “Just can't get e-nough,” New Scientist, December 20, 2006