Sagittarius, don't forget this: interpreting a photo and making a comment with content requires work and time, just like editing. All this is given for nothing.
If someone edits your photo against your wishes, politely ask them not to.
Marking each photo with a warning will make you look paranoid or insecure!
Random unsolicited edits of another person's work is not a common problem on any photography-related website with forums, apart from a dedicated retouching forum, where it is acceptable.
I'm one of the four hosts of the Wednesday Critique Thread. This weekly thread has run for 400 weeks, on DPR and now on this forum, and this is the disclaimer that we post in the introduction to the thread each and every week:
"It is understood that unless the original poster specifically states that they do not want an altered image posted that you are free to alter the posted image and repost it in a reply for C&C purposes (no use for other purposes!). That reposted image may remain permanently or you may remove it after a short period of time if you prefer. No copyright disputes here!"
If you post in the Critique thread and do NOT want anyone to visually show you the edits they recommend, just say so in your post.
I appreciate anyone who would take the time to demonstrate for me any suggestions they have for my own images. I have learned so much from them over the years. If someone shows me an edit I don't particularly like, I still appreciate the time they took to edit and share.
I'm with minniev. But only for the weekly C&C thread. We put images up in this thread to discuss and critique. Alternative crops in particular are often discussed. It is usually much easier and more precise to do the crop then post and explain why. The discussions and suggestions are always (well, almost always) conducted in a positive, constructive way. Something that makes a difference is flat v threaded forum organization. It is easier for a complex discussion to take place and be followed in threaded view. Discussion might flow around whether or not an object might be removed in an image. Edited examples might be posted.
Within that thread I consider altering, reposting images as part of discussing a point, to be entirely acceptable. I would insist that it be done in a constructive, respectful way.
An extra note: In another photography forum where I've invested significant time, there was a text box on the Profile page that one could add a sentence or two. We don't have that here but perhaps we could... The message we put there automatically appeared at the bottom of any post we made. Some members put their request that no one edit their photos in that box. Others added a quote they found inspirational. Here is what I put there.
-It is fine for others to edit my images for the purpose of reposting on my threads or responding to my posts-
Apparently it is custom on that forum to ask permission to edit somebody else's image and you gave a permanent permission. Otherwise why would you do this.
It's a big forum with more subsections than this one has, and some sections have different rules than others. There are some sections, like our critique section here, that lay out the rules in the section intro for implied permission to edit unless the poster indicates they don't want to see edits. The message saved me and others from having to remember or recheck each section's particular guidelines and add our preferences to each post.
Copyright. That's a laugh. Unless you posses a small fortune to give away to lawyers. Otherwise, it's pretty meaningless.
My wife is an artist. Screenprinting. She continually loses original designs to T shirt shops along the North Carolina coast. She produces and sells a design for a few months, then we see exact copies in those shops. They are copyrighted but, of course, the copy is missing that part of the print.
We could spend a few thousand dollars per to maybe get those shops to Cease and Desist. But no good way to get any punitive damages from them. They have to ignore the C&D order before it goes further. So, the answer is to simply ignore them and produce a new design to sell. And, of course, the cycle repeats.
It's the same with my lighthouse photography. I sell prints of the NC houses and have seen shops selling the same where I can tell someone took one of my prints and shot that and printed the resulting image. And, just like her stuff, the copyright data which was part of the original print is a blurry spot now. Oh, well. It was fun while it lasted.
As for online posting, do not post anything you don't want to see used by others elsewhere. It is going to happen. Edited or not. And don't for a moment think a copyright notice will do diddly/squat. Unless you have the large bags of cash required to go after such.
Thats your opinion about the NORM, if your images to be untouched write it down in your signature.
PS: We dont have signatures here do we? We should have I think.
So your opinion is that NORM is to take somebody else's image and do whatever you want with it. Common etiquette and common courtesy do not exist anymore in public place.