In September 2021, social media users enthusiastically shared an inaccurate warning about special software and apps that could, supposedly, remove strategically placed stickers and emojis from photos of children posted online, thus potentially leaving kids exposed or with their privacy violated online.
The meme had been shared very widely, on Facebook in particular, throughout 2020 and 2021, but enjoyed a resurgence in September, for reasons that are unclear. The screenshot below shows just a selection of examples from Facebook, demonstrating its popularity on that platform:
It contained the following text:
So apparently there's [sic] apps that can remove stickers from Facebook pictures..
I've had a google and I have found it to be true..
After a bit of digging I found that the only way to censor your images it [sic] actually rub it out with the eraser tool..
adding stickers adds layers to the image that can be removed quite easily with the right apps or software..
Please be cautious when posting pictures of your babies when censored with Facebook stickers...
In reality, no apps exist that can "remove layers" from photos uploaded to Facebook or other social networks, thus leaving children and others open to unwanted exposure. Though well-meaning, such warnings were fundamentally inaccurate, and we are issuing a rating of "False."
The overwhelming majority of images and photos uploaded to, and downloaded from, social networks like Facebook and its subsidiary Instagram, are in one of two file formats: JPEG (or JPG) or PNG. Those formats consist of only one image layer, which means it is not possible to extract, edit, or remove a background layer (e.g., an original photograph) or a top layer (e.g. a "sticker" added using Facebook's image editing tool).
The Facebook and Instagram "stories" feature does use image layers, so there is a grain of truth in the assertion that "adding stickers adds layers to the image." That layering is what allows a user to, for example, add a sticker or a block of text (the top layer) on top of a photograph (the background layer).
However, once the resulting composite image is uploaded to Facebook or Instagram, those multiple layers are "collapsed" or "flattened" into one layer. Another user could download the resulting image but could not unilaterally gain access to the original separate layers and could not, as the viral warning claims, "remove" one of those layers in order to reveal a hidden part of the other layer.
The only way in which an individual could gain access to the original layers of a composite image (for example a photo of a baby and a "sticker" placed over the face) would be if the creator shared the original files with the individual, or shared a file from an image editor, such as a "PSD" file in Adobe Photoshop, or an "XCF" file in GIMP. In such a scenario, the concern over unwanted access to raw images would not arise, because the creator would be voluntarily sharing them anyway.
Clone stamping works by taking a single-layer image, selecting a sample from its background, and then covering over an object so as to give the appearance of having "removed" that object. However, background cloning can only simulate the background behind an object — if the image file consists of only one layer, it is not possible for the user to actually remove an object and see the real background that was hidden by that object.