The orphan works proposal, which is being deliberated by Congress as part of U.S. copyright law, "shows just how dangerous this can be when it comes to copyright because it essentially creates immediately 'orphaned' images that can then be used for free because it's no longer possible to contact the photographer and get the proper permission," said Grover Sanschagrin, co-founder of PhotoShelter, an online image archive and distribution system for serious and professional photographers.
Still, the notion that social networks may be abusing image metadata is not altogether new, and photographers should know what they're getting into when they use free sites like Facebook to post their photos, some say.
"Professional photographers know that when you use free social media you're at their mercy, so to rely solely on Facebook or Twitter for something like a portfolio when you use nothing else and then complain about it kind of makes you look foolish," said Megan McGory, a freelance news photographer based in Lisbon, Connecticut.
Deleting metadata could be an issue, on the other hand, if someone is trying to track cases of copyright infringement or even stolen cameras, McGory added. "The camera's serial number is in the metadata and you can find sites using images taken with your camera that way," she said.
Facebook, Twitter and Flickr did not immediately respond to requests for comment on this story.