Just a kettle of legal headaches.
Uncle Pete - Why do you think editorial is a kettle of legal headaches? My understanding is that maybe it is - but not likely for the contributor or the agency.
The legal headache may come in with the the end user/buyer though.
I shoot picture of something in a public place - say a demonstration or an event. No harm there.
I upload it to an agency and they make it available as an editorial image only. No harm there either.
The agency sells usage rights for that image that is my copyright. Still no harm there.
Seems to me the only complication thereafter comes in when the buyer uses is for a purpose for which it was not intended. If they stick to the "editorial only" instruction clearly labeled on the box, there should be no problem.
Newspaper uses picture to accompany a story about demonstrations in general - no problem.
Newspaper uses picture of clearly identifiable individuals to accompany a story about muslim radical extremists. Picture in agency is clearly captioned to be that of Sikhs peacefully demonstrating that Americans can't tell the difference between their faith and Islam. Big problem . . . for the newspaper that is.
Ad agency uses the picture with people in it for a campaign - possible problem if they kick up a fuss.
The point is that if there is a legal issue, it's not likely to be a legal issue for the agency or the contributor - it's the end user that need to be aware of what an editorial image is and how it can or cannot be used.