This weekend, an anonymous poster on the New York Craigslist's "rants & raves" section shared the results of an study he says his Midtown Manhattan restaurant conducted to determine why their "service just seems super slow".
The poster says they compared security recordings from 2004 and 2014 and came to the conclusion that smartphone-obsessed customers were to blame. Where an average mealtime in 2004 was 65 minutes, 10 years later it had increased to 115 minutes.
Patrons were spending too much time playing with their phones and taking pictures of each other and their meals, the rant continues.
"We are grateful for everyone who comes into our restaurant, after all there are so many choices out there," the poster concludes. "But can you please be a bit more considerate?"
By Monday the Craigslist diatribe had been flagged for removal and was no longer available on the site - but not before the entire thing had been copied by Distractify's Maia McCann, where it was shared on Facebook by more than half a million people and liked by over 755,000.
The post seems like the sort of apocryphal urban legend that sweeps through the internet with some regularity, but the subject of mobile phone etiquette at restaurants has obviously touched a nerve.
"I'd bet real, actual, non-digital money that it was a well-worded, carefully thought-out piece of creative writing by either a frustrated restaurant employee or a fed-up customer," writes Bustle's Lucia Peters.
Nevertheless, she says, "it's generally true that we're all chained to our phones these days".
"Going out with a bunch of friends only to ignore them in favour of your phone kind of defeats the whole purpose of the outing in a first place," she writes.
She cites a recent study from Essex University that finds just the presence of a smartphone diminishes the quality of conversation.
Researchers found that a phone placed on a table during dining decreased trust shared by the mealtime study participants.
"We found evidence mobiles can have negative effects on closeness, connection and conversation quality," Essex researcher Andrew Przybylski told the Telegraph.
"The presence of a mobile phone may orient individuals to thinking of other people and events outside their immediate social context. In doing so, they divert attention away from a presently occurring interpersonal experience to focus on a multitude of other concerns and interests."
A team from Virginia Tech University confirmed the Essex lab-based research in a follow-up study conducted in real-world situations.
Boston Herald food blogger Kerry J Byrne admits that she takes pictures of almost every meal she eats in restaurants.
"The obsession with so-called 'food porn' runs through society, with photos of virtually every meal in America instantly uploaded to Instagram, Facebook or Twitter," she writes. "Some future society will uncover Instagram's servers and be shocked to learn of a strange people from the past that took and shared photos of everything they ate."
Gothamist's Rebecca Fishbein says that "phone zombies" are taking over New York City - "in our streets, on our sidewalks, in our park" and in restaurants.
Although the posting may be made up, writes Kitchenette's CA Pinkham, there's more than enough truth in the message it conveys:
"I can't count the number of times I had customers not eat their food for the first five minutes after it was at the table, then complain that it was cold. People bumping into other tables because they were looking at their phones is also ringing a familiar bell. Also, I swear to God every time I see someone take a picture of their food in a restaurant, I want to brain them with their plate."
Blogger Mark Maynard says that smartphones, "the advent of the selfie and the rapid proliferation of food review sites" are changing the restaurant business. That, however, isn't necessarily a bad thing.
"People who own restaurants now have more of an insight as to how their customers are thinking," he writes. "Also, I wouldn't imagine that it hurts to have people sharing images of your food."
For some restaurants, however, that's just not good enough. In 2012, Turner's restaurant in Birmingham announced it was instituting an outright ban on smartphone use.
"Mealtimes should be about savouring food and enjoying the company you're with, not sending e-mails, texts and checking Facebook," restaurant owner Richard Turner told the Mirror.
Bucato, a Los Angeles-area restaurant, did the same in 2013.
But why stop at mobile phones? Eat, a restaurant in New York City, has designated the first Sunday of every month as a "silent dinner", where patrons are forbidden to speak at all.
A bit overboard, perhaps. But fans of the restaurant's service say it is a welcome balm to the information and sonic overload of life in the big city.
A full four-course selfie/texting/chatter-free meal clocks in at just 90 minutes.