To chip in or not to chip in...
I work in the graphics industry and am using photographs and images from many sources all day long. My understanding is, you open yourself to legal action if you take an image from any source without the owners permission ( the owner of the image). However, the subject matter may also have ownership or be trademarked and then you would need their permission to use that too.
The comment regarding the angel of the north, if I was to take a picture of it and reproduced it for profit or reward, by rights I should get, in writing, consent to use it. The same goes for people in pictures. Up to a certain number of recognisable faces, I have to check that a model release document has been signed for how I intend to use their likeness. Now as I deal with image libraries, this is a very straight forward thing to do.
Surprisingly many things can be trade marked, logo designs, slogans and even buildings. We once used an image of Sydney Opera House from an image library but failed to check its status. Latterly it was discovered that it (the building) was trade marked and we did not have permission to use it. Lesson learnt! No legal action taken, just had to remove it. And this is where the system gets a bit grey. More often than not, if you use the image or likeness of something in a good light, the owners tend to leave you alone. Use it in a negative way and they may contact you to stop using it, or pay the relevant image usage costs. I've not heard of many cases making it to court, nor mega bucks being paid for unlawful use.
As Widu stated, their use of images from the net is of products, products they sell, images taken by the manufacturer. Technically, this is wrong to do so. In common practice, the manufactures don't care as you are stocking their item and more than likely with a quick email you could get the image directly from them (in practice, about a week after you don't need it anymore, but that just may be me). They are more likely to come down on you if you don't stock their item, but are using it to advertise a cheap knock off.
then we move on to image rights on the net. I believe it was stated some posts back that an image needs to carry a copywriter mark to be protected. this is more or less correct. If you really want to make sure your images are protected, then yes, copywriter mark them, but you must also be able to prove ownership of the image (a negative was great for this, but these days it needs to be the digital raw file). However, the internet is so vast, it's damn near impossible to police.
then you move on to intellectual property. Who owns the idea of something and what constitutes enough of a change from one idea to another to be described as an original idea. Moreover we are now into the realm of patents, which is not my area, so I will shut up.
with regards to copying of designs shown on this forum again falls into a grey area. If you have posted up a design of something into a public forum without trade marking or patenting, then you have gifted it to the world I'm afraid. And it is a dilemma for the makers on here, you want to showcase your work to get sales, but by doing so in a public way, you no longer control who has seen or can copy that design.
This is often seen in the fashion world. The big designers showcase their latest designs and about a week later a diluted form of it is on the high street. What makes the original stand apart from the clones and wannabes is the quality of the craftsmanship, Dreadhead has by the bucket load.
So I've rambled on, but I will finish with a little personal aside. Be carful trying to pass off something as your own. I once interviewed someone for a designers job and they showed me some examples of their work. One really caught my eye. I enquired about it, when did you design this, is this solely your work, tell me about the project, etc. after five minutes of the designer getting quite excited about the design being their original idea etc, I stopped them and got my own portfolio out and showed them the exact same design I had done. One very red faced applicant was not surprised to hear they hadn't got the job.
