Everyone talks about FaceApp, an application that can modify your image to look younger than your real life or older. Thousands of people are publishing the results of their own experiences with social media.

But since the application was widely deployed in the last few days, some have raised concerns about the terms and conditions that most users of the app would agree to without actually reading.

It was reported that Facebook company follows a policy unfair to users of the application, and delete most images uploaded to the application within 48 hours of uploading.

The company said it carried only the images chosen by the users for editing, not the other additional images. The application of Facebook is not new. For the first time in two years, headlines have been published through the application of "race change". The application was said to have turned the faces of people from one ethnic group to another, an advantage that aroused angry reactions, so it was quickly deleted. The application, which has recently been widely distributed around the world, can turn facial expressions into smiling or angry, as well as modifying make-up types. Users were shocked when they read an app developer, Joshua Nozi, who wrote, "The application of FacePap was carrying a collection of special pictures of people from their smartphones, without their permission."

The French security researcher, who uses the pseudonym Elliott Alderson, investigated Nozi's claims and found that the application carried no images other than the users had decided to send.

Others said: "FaceUp" may use data gathered from user images to train facial recognition algorithms.

"We do not use pictures to train facial recognition, just to edit the image," said Yaroslav Goncharov, chief executive of the company.

Some ask: Why does FaceUp need to upload images as long as the application is capable of processing images on smartphones without having to upload them?