[jurjenh]

What about other options? Dead/underperforming pixels seem to be a good fingerprint as well I believe.

Would be a whole different level of identification, but would lead to multiple ways to detect photos taken by the same camera.

[qq66]

Most images uploaded to the Web are not at full resolution -- it would be hard to fingerprint individual pixels.

[pavel_lishin]

Interesting, but you'd need a large corpus of pictures to compare - not quite as quick as reading EXIF data.