Meta's new AI detection tool, previewed this week alongside the launch of its image-generation model Muse Image, failed to identify some of its own AI-generated images once they were cropped, according to a Reuters analysis published July 10.
In an analysis of 40 images generated using Muse Image, Reuters found the detection tool verified all of the original AI-generated images but failed to verify 55% of the same images after they were cropped to approximately one-third to one-half of their original size.
Meta claims on its website that the preview detection tool can identify its own AI-generated images, even if cropped, through an invisible watermarking system called Content Seal embedded in every Muse Image output. However, when questioned about the Reuters findings, Meta acknowledged that the tool was only a preview and that the watermark signal may be lost if an image is heavily cropped.
The finding highlights the challenges of verifying AI-generated content after common alterations — a limitation that could make it harder to identify deepfakes online during a busy election year that includes the U.S. midterms. Rival tech companies Google and OpenAI have similarly cautioned that their own detection tools are not foolproof against image-alteration techniques.
Siwei Lyu, a computer science professor at SUNY Buffalo who researches AI image forensics, noted that watermark-based systems have inherent limitations. "Watermark-based methods can be highly effective when the watermark remains intact, but any modification that removes or weakens the embedded signal — such as cropping, resizing, heavy compression, or editing — may reduce their effectiveness," Lyu said.
The issue is particularly pressing given Meta's Oversight Board called on the company in March to do more to address the "proliferation of deceptive AI-generated content" on its platforms and invest in stronger detection tools.
Despite the limitations, UC Berkeley AI researcher Sarah Barrington sees promise: "Like many preventive cybersecurity or physical security measures, it may not be fully watertight, but even if we catch only 90% of cases, that's still a great leap from 0."
