If Alice is a photographer, she takes a photo, owns the copyright and posts it on her public website, then Bob links to that photo on his public website, is he infringing on her copyright? Does it matter if the link is an <a> vs an <img>? To be clear, his server is not serving the image, only HTML that directs browsers to the image.
Alternatively, consider the following cases.
- Clickable link to a page on Alice's site that contains the image
- Clickable link directly to the image
- Clickable link directly to the image with a note suggesting that users use a plugin like Hover Zoom (this allows the user to hover her mouse pointer over the link and see a preview of the image without leaving the current page)
- Clickable link to the image and Bob makes his own plugin that changes the link into a displayed image
- Embedding the image so that it displays on Bob's page, but is still served from Alice's server
- Embedding the image and serving it from Bob's server
I am pretty sure that the first scenario is okay and that the last one is not, but at what point does Bob cross the line?
This question is very similar, but is more focused on iframes and does not quite address my question:
What if Bob only posted a thumbnail version of the image? Is that fair use or does he have to be a search engine? If it is fair use, how much smaller does it have to bee?