Over the past week, Instagram and Facebook users started reporting that the photo-sharing app has locked them out of their accounts, and is asking for photo IDs.

Apparently, both the sites locked dozens of users out of their accounts over security concerns, and asked users for copies of Government-approved photo IDs to grant them access to their accounts.

CNET first covered these incidents on Tuesday, Jan. 22, and reports piled up over the week. The issues reportedly occurred as a result of Instagram's new terms of service, which came into effect on Jan. 19.

Users flocked to Yahoo Answers and flooded it with threads and questions, worried that they had lost access to their Instagram accounts for no apparent reason. Being required to provide their photo IDs just raised even more questions, and many wondered whether it was a phishing scam.

The ID requests turned out to be legitimate, coming from Instagram and Facebook, the social networking giant that now owns the photo-sharing app.

"Your account has been secured and requires account validation. Please login to Instagram.com from your desktop to validate your identity," read the message.

The desktop validation process requires the user to upload a photo of a government-issued ID by Feb. 1. Despite many users' worries, this request did not come from a hacker trying to gain access to their personal information.

"Instagram occasionally removes accounts due to violation of terms and, depending on the violation, may ask people to upload IDs for verification purposes," a spokesperson for Facebook told CNET.

In other words, such identification is necessary when the social networks suspect that their terms of services have been violated. Providing the required identification aims to confirm who is behind the said account, and perhaps to ensure that the user is old enough - the minimum age to use both Facebook and Instagram is 13.

On the other hand, a puzzling aspect is the fact that Instagram, unlike Facebook, does not require users to provide their real names. Consequently, it seems a bit strange that the photo-sharing service would not ask for one's real name, but demand the official ID. The social networking giant declined to offer any further comments on the matter.

Meanwhile, Instagram reserves the right to "refuse access to the Service to anyone for any reason at any time."