A dog tapping away at a computer keyboard turns to another dog and says, "On the Internet, nobody knows you're a dog."
The cartoon by Peter Steiner, which first appeared in The New Yorker in July 1993, perfectly encapsulates the world we live in today.
How do you trust someone to be who they say they are on the Internet?
The question has bubbled up again after news broke that Notre Dame linebacker Manti Te'o fell for a "catfish," someone who fakes an identity online to finagle his or her way into a fraudulent romantic relationship.
We do our best to avoid being duped. But it's not always easy.
"This is so sad, this has happened to me a couple of times in the past when I first started dealing with internet dating," posted Ronnie Williams in a CNN story on the hoax. "I got my heart broken just like this, so trust me, this is a creepy, deceptive low life way of either playing with someones emotions or getting money or information out of them."
Twitter offers verified accounts to help us discern public figures from their imitators. Even President Barack Obama in a Reddit chat posted a picture of himself to verify his identity.
At CNN, we Skype with eyewitnesses on the scene of breaking news or have them stream live video of themselves and landmarks to verify that they really are where they say they are. At iReport, we call people on the phone to confirm their submissions.
Te'o, for instance, says he was scammed digitally and over the phone .
As naive as someone who falls for a fake online girlfriend may seem, it's not hard to do, even for a sports superstar, said Nev Schulman, who hosts the MTV reality show "Catfish."
"When you make a connection with someone online, oftentimes it feels a little limited, but also safe," Schulman told MTV News. "Then people open up and get very close without scrutinizing the other person."
Still, we take steps. Step one: We Google. Relentlessly.
Before a blind date. Before picking up a concert ticket we bought off someone. Before hiring someone to rake our yard.
Because on the Internet, we the dog catchers have our work cut out for us.
Followers reply with tweets of condolences after "girlfriend" Lennay Kekua's apparent death.
September 16: Te'o tweets, "I know you're there" with a picture of him pointing to the sky.
September 23: Te'o tweets a link to a picture of two beams of light descending
on him during the Michigan game and writes: This brought tears to my
eyes! The two beams of light! My guardian angels!!! I miss you!!
December 6: Te'o receives a phone call while at an awards show from the phone number of his dead girlfriend. The woman says she's not dead.
December 8: Te'o goes to the Heisman Trophy presentation in New York, where he finishes as runner-up to Johnny Manziel.
Before December 25: A person using that number continues to call, but Te'o does not answer.
Christmas break: Te'o discusses the situation with his parents.
December 26: Te'o calls Head Coach Brian Kelly and Defensive Coordinator Bob Diaco and informs them of the situation.
December 27: Te'o meets with athletics director Jack Swarbrick and they discuss the situation.
After December 27: The University hires a nationally known investigative firm to look into the matter.
January 4: The private investigators give Notre Dame their report.
January 5: Swarbrick meets with the Te'o's family.
January 7: Te'o plays in the national championship game.
January 16: Deadspin publishes a story saying Te'o's story about the death of a girlfriend is a hoax.
Notre Dame says Te'o has been the victim of an "elaborate hoax" and a "sick joke."
What steps do you take? What are the signs you look for to verify someone's real? Were you still duped? Let us know in the comments section below.