I don't know if you've ever heard of a 'bright line rule' [0] - the idea is you have a simple rule everyone can understand and interpret in the same way, instead of a nuanced rule with lots of room for interpretation.

If you use a simple-to-follow rule like "no editing except to crop and correct color balance" that's easy to understand and follow.

When you allow some manipulation as long as it's noted, editors will composite a celebrity's face onto a model's body for the front page and note it's as a fake in tiny text in a contents list three pages away. Far-fetched? Newsweek have already done it [1].

[0] http://en.wikipedia.org/wiki/Bright_line_rule [1] http://www.nytimes.com/2005/03/03/business/media/03mag.html

"Conspiracy theorists don't need reasons to argue."

Yes, but that's still no reason to release a known "fake" image. Also, you can tag it with captions and disclosures, and someone might still link to the image as "look, there's no antenna on his head unlike other photos, proving the landing is a fake".

"Yet, in this case the reporter knows to which degree the information was tampered with - and the reporter has no problem verifying it either."

Publications have a no-doctored-images policy, it doesn't allow for exceptions, even if the length of the manipulation is known, especially when the original is available.

Actually, it is the other way round - not the journalist has to know how much tampering has occured - I, the reader, have to trust the newspaper to get everything right in their reporting. Unlike in science, journalists often can not or do not want to reveal their sources and attribute every statement. Therefore, I need to be able to trust the newspaper as a whole that they have appropriate safeguards in place to detect and avoid false information and tampered images. By being holier than the pope, the newspaper supports this trust.

"Conspiracy theorists don't need reasons to argue."

And people brainwashed by mainstream propaganda don't need reasons to repeat what they've heard on TV ;-)