What are image moderation services?

Question

Images

Tell the services for moderating images so that the service receives an image at the input, and at the output it gives an answer whether this image is normal or not (porn, advertising, etc.).
The idea is similar to https://rucaptcha.com/. Where the input is a picture, and the output is text from the image. But you only need to receive spam in response or not.

Answer 1

Amazon Turk
and similar services