For years, the Internet has put an endless supply of images in front of us and made it easy for us to collect those images for our own personal use. And there's a certain amount of "personal use" that's allowed under fair use copyright laws. But after a decade or two of pretty much getting away with hoarding images and recycling them on our websites, message boards, then Myspace, then Facebook, and now Pinterest — software has caught up to us.
All you have to do is open up a Google Image Search window, click on the little camera icon in the search field and upload your photo or type in the photo's URL and Google will happily return to you a nightmare of search results where that photo is currently being used online.
And if Google is happy to provide this service for free, imagine what kind of image-recognition and tracking software major companies can afford!
I have long maintained that the Internet makes using images to "quote" someone a possibility. If you use someone's image, you can easily caption it with proper credit and/or link back to the source of the photo. In my opinion, this would be the same as using quotation marks in a paragraph to quote something someone has said without getting nailed for plagiarism.
But not everyone does that. The thought doesn't even occur to many people. I personally have found several of my images being used on blogs around the world, many of them do give me credit (hard not to with that watermark across them) and give the URL to where they found my photo. But not all of them bother with this, and none of them have made the attempt to simply contact me (easy enough to do from any of the places I post photos) to politely ask for permission to use my images.
There are some big companies out there whose business it is to buy, sell, and rent images for commercial use and it looks like some of them are getting serious about tracking down those images and making sure they get paid for them.
This seems to be a subject that is currently getting a lot of attention and it looks like some companies are skipping the traditional (but not required) step of sending "cease and desist" orders before issuing a bill and threatening to sue.
Remember, if it doesn't belong to you, it belongs to someone else; if you don't have permission to use the image, don't.