Appeal to Popularity

In this argument things are presumed to be true because the majority believes that it is true. However, it's important to realise that the majority cannot "elect" the truth, truth exists independently whether people believe it or not. We can be sure that the vast majority believed the Earth was flat at 1500BCE, yet if a lot of people believe in something this doesn't make it to be true

Example: "Surely billions of people can't be wrong regarding the existence of God"

Claims requires evidence, and "extraordinary claims require extraordinary evidence". Anybody who watches someone like David Copperfield's grand illusions knows how easy it is to fool people. However it should be noted that there's a big difference between an appeal to popularity and to an argument from an expert, for if an astronomer says that the Earth revolves around the Sun then we can be more certain he's correct for he investigated the subject with skepticism and looked at the evidence.