Tom MacMaster, a 40-year-old American, wrote online for years under the pseudonym Amina Arraf, supposedly a lesbian Syrian blogger. (Screengrab/Facebook)

“On the Internet, nobody knows you’re a dog,” reads a New Yorker cartoon from 1993.

Almost two decades later, the subterfuge of the Internet still remains one of its defining traits. This weekend, a new example of it was exposed in an elaborate hoax.

“A Gay Girl in Damascus,” a blog reported on around the world, including by BlogPost, written by Amina Arraf, a half-American, half-Syrian lesbian blogger. Arraf had existed and interacted with folks online for over five years.

In real life, though, Arraf only existed in the mind of a 40-year-old American man named Tom MacMaster.

On Sunday, MacMaster apologized on his blog for the hoax, as his readers expressed outrage over the deceit and over the attention that had been taken away from the increasingly violent government crackdown in Syria.

Elizabeth Flock and I spent the last three days speaking to MacMaster and his wife on the phone, asking him to admit writing the blog, and tracking down connections between him and Amina online.

On Monday we’ll write a quick behind-the-scenes story of what happened, but here’s our full report on Tom MacMaster’s hoax of Amina Arraf.