A significant drop in Instagram's daily active users was recorded by the applications-traffic tracker AppData after the photo-sharing app recently acquired by Facebook Inc. (NASDAQ:FB) announced on Dec. 17 forthcoming changes in its privacy policy and terms of service, or TOS, the New York Post reported.

Many users interpreted the proposed changes to mean Instagram would be able to sell their photos for advertising and promotions without any compensation to them.

As a result, many of them -- encompassing celebrities such as pop singer Justin Bieber and reality-television star Kim Kardashian -- expressed their intent to abandon the app.

In response, Instagram has apparently rescinded its proposed changes and gone back to its old policy, the New York Post said.

Instagram's daily active users dropped to 12.4 million on Dec. 26 from 16.4 million circa Dec. 17, according to AppData figures cited by the newspaper.

“[We are] pretty sure the decline in Instagram users was due to the terms of service announcement,” AppData told the Post.

However, several sources have indicated that AppData's numbers may not be all that accurate. One reason is that AppData can track stats only on a subset of users -- those whose Facebook and Instagram accounts are linked -- according to the New York Observer.

Moreover, the mobile-news site Quartz noted that AppData's figures showed the drop in Instagram users did not happen immediately, but more or less coincided with the Christmas holiday, which led the Observer to point out most of the drop may actually have been caused by people disconnecting from social media and spending time with their families during the holiday weekend.

Along a similar line, The Next Web reported that other Facebook-associated apps such as FarmVille, Pinterest, and Spotify also had dips in their daily active users over the same period as Instagram.

In any case, the New York Post reported Bieber has remained active on Instagram, but Kardashian -- who is the app's most followed user -- has not posted a photo since the announcement of its proposed changes on Dec. 17.