I think your best bet would be to have a brief conversation with a law expert, perhaps in a uni near you, or your friendly neighbourhood lawyer about that. If you are not claiming what you paste as your own creation, or use it for monetary gain, you refer to it as part of a conversation, in the USA there is a provision for fair usage, as part of an argument, illustration. Nobody could or would enforce such " infringement" , except nick pickers that want to stir trouble, trying to be big by attempting to make others small. But people should be proud of their work and have it recognized, if so, they should state that clearly. Some of the images on Google do that by splaying their logo over the pictures , some are grouped and bracketed. The above Wonoto creation is from a paper 2002? unable to contact the family. All the credit to him, from all of us. His paper an interesting read, even has Carl Sagan lecturing in the beginning. Most creators should be tickled pink to have their work thusly spread. imho.