Instagram, faced with thousands of angry users upset by news that the popular app would let advertisers pick and choose among user-posted photos for ads, reversed course and said late Tuesday it won't allow that.

The proposed change to the old-timey, photo-sharing service' privacy policy was announced Monday, with Instagram saying users had until Jan. 16 to voice their views. They didn't need that much time. It took way less than 24 hours.

"One of the main reasons these documents don’t take effect immediately, but instead 30 days from now, is that we wanted to make sure you had an opportunity to raise any concerns. You’ve done that and are doing that, and that will help us provide the clarity you deserve," said Kevin Systrom, Instagram co-founder, in a blog post Tuesday.

"Instagram users own their content and Instagram does not claim any ownership rights over your photos. Nothing about this has changed."

Systrom also said that "the language we proposed also raised question about whether your photos can be part of an advertisement. We do not have plans for anything like this and because of that we’re going to remove the language that raised the question."

Privacy advocates and users were interpreting the dense legalese of Instagram's proposed new policy as permission for Instagram to use all publicly shared images like its stockpile of stock photos, farming out your bathroom mirror self-portraits, or whatever, to advertisers willing to pay. (Pay Facebook via Instagram — not pay you and/or the photographer. Facebook recently bought Instagram.)

"Really, Instagram? Purchased for $1B in inflated FB stock and you're going to start selling members' pictures? Street Artists best leave now," read one tweet of warning, as #BoycottInstagram began trending on Twitter.

"I came late to Instagram, but I will leave early," noted another.

For what it's worth, Instagram wasn't claiming it owned your "Content" (with a capital "C"). It was just apparently going to sell it like it did. As the original new user agreement read:

Instagram does not claim ownership of any Content that you post on or through the Service. Instead, you hereby grant to Instagram a non-exclusive, fully paid and royalty-free, transferable, sub-licensable, worldwide license to use the Content that you post on or through the Service, except that you can control who can view certain of your Content and activities on the Service as described in the Service's Privacy Policy, available here: http://instagram.com/legal/privacy/.

Users were given the option of deleting their accounts by Jan. 16. After that, Instagram had said, it's a done deal, with no way to opt out. Also, photos that were posted prior to Jan. 16 were to be eligible for licensing by Instagram for an amount of time not specified in the new privacy policy.

As one Twitter user puts it, "I wish I had the strength to leave Instagram ... but I can't do it. No matter how badly it treats me."

Then again, at least some were seeing the bright side of staying: "I can understand why some people won't leave Instagram. Imagine the thrill of seeing your sandwich on somebody's billboard!"

Helen A.S. Popkin goes blah blah blah about Internet privacy, then asks you to follow her on Twitter and/or Facebook. Also, Google+.

This story was updated at 5:20 p.m. ET Tuesday.