On the Internet, nobody knows you're a dog

On the internet, it is hard to tell who someone really is. People can create fake identities or pretend to be someone they're not. For example, some people might post pictures on the internet of their dog, and pretend that it is themselves. In this way, no one else can tell that the person posting is not actually a dog - they can only tell from the picture. So, even though you can talk and share pictures on the internet, it is hard to tell who people really are. That's why people say "on the internet, nobody knows you're a dog."