How much effort do you put towards images? Google's image recognition is unbelievable

I think that if you understand the algorithms used to detect images, then you are no conceed about whether said image is published or not.

As an example, Microsoft's (Bing's) image recognition scales an image to 277 X 277 pixels, breaks the image into 20 slices, and then looks for edges in the slices.

Understanding the algorithm also tells you how to defeat the algorithm.