In recent years, image licensing companies have been created that earn most of their money, not from the actual licensing of images, but from filing copyright infringement lawsuits. Some of their images may have previously been unlicensed and innocently used for years on websites, but now that they are copyrighted, they must be licensed for you to use them. Many of their images are nothing special and most people would not pay the exorbitant licensing fees to use them. However, people may innocently download the images from another site, such as a site that says the images are free to use, and then find themselves subject to copyright infringement.
Most of these companies are located in other countries than the United States, but that does not deter them from going after anyone. They just hire local lawyers to pursue the cases in your local courts. They make their money from settlements or lawsuits, so they will pursue anyone.
To see how some of these companies operate, do web searches for topics such as “image copyright scams,” “image copyright rip offs,” or “copyright infringement.”