As the November 8 election drew near, hundreds of threatening messages flooded Alefantis's Instagram account
It ended in death threats against a small business owner -- and became a shocking case study in the dangers of the growing prevalence of "fake news."
The fake news phenomenon has sent major internet companies scrambling to respond amid claims that bogus reports that proliferated ahead of the US presidential election may have skewed the result.
This episode started in October after WikiLeaks published a batch of hacked emails from John Podesta, the chairman of Clinton's presidential campaign. Journalists and others have pored over the tens of thousands of stolen communications in search of politically relevant information.
But some readers honed in on a handful of innocuous messages recounting a Clinton fundraiser involving James Alefantis, the owner of a popular Washington pizzeria called Comet.
Almost immediately, "pizzagate" was born as right-leaning conspiracy theorists on the discussion sites 4chan and Reddit claimed Comet was not just a purveyor of pizza and beer but in fact a sinister front hiding a politically connected pedophile ring. Word quickly spread.
"They've apparently uncovered an elite child trafficking network which celebrates its tendencies using code words and disturbing artworks," alleged the website The Vigilant Citizen, which claims to study symbols.
In this world, nothing was innocent. Nude paintings on the walls were suspect. Patterns on a child's dress or the menu revealed supposed pedophile symbols and a picture of a girl playing with masking tape was evidence of sexual abuse.
Theorists even resorted to the French language in search of potential codes: the name James Alefantis was supposedly derived from the French phrase for "I love children."
As the November 8 election drew near, hundreds of threatening messages flooded Alefantis's Instagram account. The restaurant's Facebook page was also barraged with negative comments.
"My first reaction was there's a bunch of crazies out there. Everyone is hyped up about the election, so it will go away," Alefantis told AFP. "But instead it went the other direction."
After Donald Trump's shock victory, things got even worse.
"It was a combination of people telling us that they were going to come and do something or that we've been found out and that we should show where the tunnels are," Alefantis told AFP.
To all appearances, there is nothing untoward about Comet. Friendly and stylish, the restaurant is divided into several areas, including one with ping-pong and Fussball tables, and stages for alternative rock performances in the evening.
"Comet is a place that bridges," said neighborhood resident Leslie Harris who is helping the restaurant respond to the onslaught. "In the early evening, people with strollers bring their little kids in for pizzas."
"It's an adult hang out but the irony of it is that it has also been this safe place for our teenagers."
Alefantis believes the "coordinated and orchestrated attack" was in reality retribution for his political views and his support of Democrats.
"I'm an independent business owner and I feel I have the right to make decisions on who I support and how I utilize my resources," he said.
Alefantis has contacted the local police and the Federal Bureau of Investigation but there is little that can be done for the time being. Under pressure, Reddit has closed the "pizzagate" discussion, citing "repeated violations of the terms of our content policy."
But the attacks have not ended.
"It would be like whack-a-mole," said Claire Wardle of the Tow Center for Digital Journalism. "It's impossible to regulate or to police these places so instead we have to think of other ways to give users tools to recognize what's trustworthy or not."
In the meantime, Alefantis is calling for greater social media awareness.
"It has to be recognized within the broader society that social media can be weaponized," he said. "You can be easily taken down or destroyed by this sort of attacks."