I was contacted a couple days ago from someone that wanted to buy an image of mine they had seen on Flickr but they wanted a higher resolution image. I went to look at the image, and I had mistakenly uploaded it at a lower resolution as I typically upload full resolution images to Flickr.
I fix that problem by replacing the smaller image with a full sized one, then contacted the person and let them know. Thinking she could use the "buy" feature in Flickr (turns out, you can only buy your own images...but learned that later).
Never heard from her again. I haven't tried to contact her either.
But it surprised me that she was able to download the image without some sort of action on my behalf as I have "downloading" disabled on Flickr.
That would prevent downloading, right? Nope. It appears that it just makes it a slight inconvenience. Logging out of my Flickr account, and playing around, I figured out that even with downloading disabled in my settings, the "Download this Photo" arrow still appears for each image (bottom right). Clicking on this, then view all sizes, and sure enough a number of different photo sizes appear, and the Flickr version of downloading isn't possible.
But you can still right click and "Save As" the image.
I have found what I think is my solution. Under "Account-> Settings -> Privacy & Permissions" Flickr has "Largest Shared Image Size." Their recommended is "Best Display Size" (this may also be the default, as this is what I had in my account). This allows anyone to download full sized images by right clicking. Change this setting to a smaller file size, and then people are not even given the option of viewing larger file sized images.
Scrolling a few people, either they upload a limited file size or they have this feature set at a minimum value: Bryan appears to have his set at 3000 pixels. Sapna Reddy at 1600 pixels. Neuro's file size is 2048 pixels.
I am now set at 1600 pixels. I might go to 2048, but it will be one of those two moving forward.
If someone has a better system or knows a flaw in what I just did, please let me know.
Thanks...Brant