Vegaman_Dan - Thanks for the followup post

You pretty much nailed it: we aggregate links to homemade tools, organize them, categorize them, etc. Our other sites (I don't want to promote them here, but they're linked in the header of HomemadeTools.net), aggregate build threads of various types: cars, 4x4s, boats, airplanes, cabins, motorcycles. Our company, BuildThreads, Inc., is based around curating the two greatest kinds of content on DIY forums: homemade tools and build threads.
The image usage on the site is similar to Google Images; it's allowed because it's more of a reduced-size pointer or reference to the original post. Each listing also links back to the original post three times, and fully credits the original builder and site. Google Images, or Pinterest, or similar sites, seem to lack that level of properly crediting the original builder, per the unwritten laws of forum culture.
If anyone ever wanted a listing removed, we would instantly delete it. Over the years, we have had a small number (less than 5) of removal requests, but since we are fully crediting the listed builders and sites, and we send a lot of traffic to them, everyone generally seems happy.
404 - Rant understood. I clear my cookies all the time too, and am constantly clicking away scrollers and sliders. Maybe we can just stop showing it to people with the same ip/browser combo, rather than relying on the presence of a cookie.
BTW you guys can see all of our GJ tool listings here:
425 homemade tools from GarageJournal.com. And you can see all homemade tools organized by site here:
homemade tools by site.