This is a subject I have strong mixed feelings about. Over the years I have found my photos all over the net, mostly just grabbed up and used for whatever reason, mostly good (the betterment of our hobby) but here are my thoughts:
1) I believe unless otherwise stated or protected, any web image is public domain - if it is there, use it.
2) If an image is purposely protected (kept to a small size, notified as copy-protected, watermarked, etc.) because this person is making money from these then they should be respected then going out of your way digitally removing or cropping out watermark or not giving credit to the photographer or graphic artist is wrong.
I have found my images in publications, web-pages, one actually used in an ad in a magazine and even formed into a phony national magazine cover. I never have gone in a litigious way to recover any damage because in my case no damage was done - although without compensation, why should someone else receive monies from my content when I don't?
As I say, I have mixed feelings. But today most of us take photos. I'm lucky enough to say one of my photos has been sold in print over 1 million copies to date - making the book author rich and getting me mild notoriety at best.
But to date, I know of over 40 photos that have been in print and dozens more copied onto websites, all of which are mine - I'm wondering if other members have had this same problem and what they think of it.
I enjoy to hear from people asking permission to use images and often get a printed edition to add to my collection of "15 minutes of fame". None of which I hold prouder than the success of this forum and the wonderful friends I have made here.
The web is for the taking I guess - it is a major part of its success. Peer to Peer downloading has cost musical artist billions, but then again, many of these artists say it actually helps promote CD sales and especially concert sellouts.
What do you think and have you had your stuff, images, sound, writing, etc. used online or elsewhere without your permission - and what did you do about it if anything?