On the Internet, nobody knows you're a dog

"On the Internet, nobody knows you're a dog" is an adage about Internet anonymity which began as a cartoon caption by Peter Steinerand published by The New Yorker on July 5, 1993.

The cartoon features two dogs: one sitting on a chair in front of a computer, speaking the caption to a second dog sitting on the floor listening to the first.

The cartoon marks a notable moment in the history of the Internet.

It also shows how Internet communication is liberated from familiar constraints. 

Sociologist Sherry Turkle elaborates: "You can be whoever you want to be. You can completely redefine yourself if you want. You don't have to worry about the slots other people put you in as much. They don't look at your body and make assumptions. They don't hear your accent and make assumptions. All they see are your words."

in Wikipedia