> Pictures are an intellectual property of the author, if a person wants other people to spread them, he/she needs to explicitly set the allowing license.
It's more complicated than that. What actions require a license? Nobody needs a license to create a hyperlink. The concept of a "link license" was a big subject of debate in the 1990s, but after much hand-wringing and heated discussion, we converged on a permissionless model for hyperlinking on the web. I think everyone here understands the high value of frictionless linking.
Now let's suppose for the sake of argument (and without loss of generality) that this foot fetish site were just a list of hyperlinks to publicly available foot pictures in their original context. I suspect the author of the article (and a lot of other people) would still be squicked out by the foot-fetishist link-aggregator site. But what could be done about it? Permissioneless linking is a huge boon for the web and humanity. Should we add friction to linking just because foot fetish sites exist?
Okay --- what if it's not linking, but actual photo embedding? Still, we'd need to examine the costs and benefits. Embedding public content in another context is great for commentary, synthesis, and other creative transformations. People love to showcase hard work and beauty. Should we add friction to photo embeds everywhere just because some squicky foot fetishists use embeds to aggregate images? Again, it doesn't seem worth it.
Ultimately, we have to learn to let things go. There will always be people in the world who use public things in a "wrong" way: a politician you don't like may use your favorite song in a campaign; a company might use your open source library to make a product you'd prefer not to exist; or public property records might let speculators arbitrage prices in a way that seems unfair. But whenever we're tempted to Do Something about people using the public thing in the wrong way, we have to think "is this Doing Something going to be net positive? What about the value of the commons itself? Am I willing to destroy that just to Do Something about this one thing?" Most of the time, the answer is "no".