Facebook, owner of photo sharing site Instagram, stirs protests after saying it can take users’ photos for advertisements. (Karen Bleier/Getty Images)

This being the Age of Social Media, Tuesday’s extraordinary user revolt against Instagram was perhaps most easily viewed on Twitter, where shock and outrage mixed with fierce declarations swearing off the popular photo-sharing site for good.

“Really sad to have to end my luv 4 @instagram,” tweeted actress Tiffani Thiessen. “Will be deleting my account due 2 their ridiculous new terms.”

The explosion of Instagram bashing was sparked by a planned policy change that appeared to give the photo-sharing site new latitude to use images uploaded to the site, without permission and without compensation.

Many users said that, based on the new “terms of use” that Instagram announced Monday, they feared they could find themselves — or their friends, or even their children — in advertisements created by the company or by Facebook, which bought Instagram this year in a deal initially valued at $1 billion.

Instagram scrambled Tuesday to contain the controversy, issuing its own tweet midday acknowledging the complaints. Later, co-founder Kevin Systrom published a blog post saying, “To be clear: it is not our intention to sell your photos. We are working on updated language in the terms to make sure this is clear.”

But the updated language was not immediately available, leaving many users still skeptical about Instagram’s intentions. Legal experts said the “terms of use” document was remarkably expansive. Elements would apply to users as young as 13.

Fordham University law professor Susan Scafidi, an expert in fashion law, said models and other celebrities were in particular peril of seeing their images affiliated with products they did not endorse. That was less likely for ordinary people but plausible given the new Instagram policy, she said.

“It’s entirely possible that you and I could find our faces plastered across billboards associated with something you want nothing to do with,” Scafidi said. “This is basically asking everyone using Instagram to waive their right of publicity.”

Instagram was a top search query on Twitter and Google on Tuesday, and little of what was being said was kind. Advice on how to delete an Instagram account went viral. The policy is set to take effect Jan. 16.

U.S. Rep. Edward J. Markey (D-Mass.), co-chairman of the Bi-Partisan Congressional Privacy Caucus, joined the chorus of complaints Tuesday night with a sharply worded statement saying consumer privacy — especially that of children — may be at risk.

“A picture is worth a thousand words; posting one to Instagram should not cost you your privacy,” he said.

The sentence in the new “terms of use” that triggered the most user concern said, “To help us deliver interesting paid or sponsored content or promotions, you agree that a business or other entity may pay us to display your username, likeness, photos (along with any associated metadata), and/or actions you take, in connection with paid or sponsored content or promotions, without any compensation to you.”

Despite pledges to alter the language in response to complaints, the changes had not been issued hours after Systrom’s blog post. When they are made public, a key concept will be photographic licensing rights, which allow others to use images even if they are not sold outright, legal experts said.

Washington Post Chairman Donald E. Graham serves on the board of Facebook.

The controversy riled up privacy advocates in Washington and beyond, who long have been critical of the policies of Facebook. They noted that the Federal Trade Commission is monitoring that company for compliance with a binding deal that settled a privacy investigation against the company.

The policy change “fits into a very disturbing pattern” said Jeff Chester, executive director of the Center for Digital Democracy. “Facebook wants a frictionless system to collect as much information and likenesses as possible.”

After Instagram’s attempt at a reassuring blog post, the revolt showed no sign of abating. National Geographic, famous for its elegant photography, posted on its Instagram account Tuesday night that it was suspending the posting of new photos: “We are very concerned with the direction of the proposed new terms of service, and if they remain as presented we may close our account.”

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