In reality, it is the burdon of the admitter of evidence to vouche for its authenticity. For me to go into a court of law and show the jury the same pictures you show us, I would also have to include how and by whom the pictures were attained. I could not simply, naively, or moronishly say, "Here are pictures I found on the internet that show the earth is round, judge I demand that the jury be forced to prove my evidence false before they reject it."
I have a feeling I will have to present this information to you at least 5 more times in 5 different ways before you realize that you are just simply wrong to demand we prove your evidence false. It is you that must prove your evidence valid. Welcome to the world, we are not going to wipe your butt for you. Its time you do things for yourself.