Speaking of Hany Farid, his team has devised a way to spot telltale signs of image synthesis:

This ability to synthesize highly realistic images is likely to pose new challenges to the photo-forensic community. This initial exploration of the geometric consistency of DALE•E-2 synthesized images reveals that while DALL•E-2 exhibits some basic understanding of perspective geometry, synthesized images contain consistent geometric inconsistencies which, while not always visually obvious, should prove forensically useful.