Not a problem if you don't use others copyrighted images.
I hate all these companies dominating Google Images anyway so I often add '
-getty -shutterstock -alamy -123rf' etc. to my search terms to eliminate all the crap from them.
I use Google's Reverse Image Drag & Drop feature a lot to find images in different sizes or similar images.
Ha! Yeah, and I've noticed a fair amount of stuff on some of those pay sites was actually created as public domain in the first place, but some scammer claimed it as their own and uploaded it so as to collect royalties. Some are obvious, like NASA images
That said, I do sometimes buy images from them, but prefer to search all comers on Google rather than go to each site and poke around with their interface. I typically do the image-save thing with their watermarked image and do a quick mockup with it to see how it works in my overall design before deciding which image to buy.
Truth is, they can't keep skilled people from stealing their stuff, only the unskilled and lazy, which is a fair amount of the people who steal in any given situation
Is Google getting money out of this deal? Or is this just part of their "Don't be evil" philosophy? (I watched the movie "The Circle" last week ... Tom Hanks as a "bad guy"

, and an Apple/Google/FaceBook-like company.)