Fast food chain Subway is facing criticism over claims that its famous footlong sandwiches are falling short.
Subway is the world's largest fast food chain with 38,000 outlets, and more than 100,000 people have "liked" or commented on the photo, which had the caption: "Subway pls respond."
The New York Post carried out its own investigation and found four out of seven footlong sandwiches were less than the vaunted 12 inches.
Subway said the length of its sandwiches may vary slightly when its bread, which is baked at each outlet, is not made to the chain's exact specifications. It said in a statement: "We are reinforcing our policies and procedures in an effort to ensure our offerings are always consistent no matter which Subway restaurant you visit."
The original photo is no longer visible on Subway's Facebook page, although the company said it did not remove it. But lookalike pictures of the sub surfaced elsewhere on Facebook, and the backlash shows the challenge companies face with the growth of social media sites like Facebook, Twitter and YouTube.
Previously someone in Australia would not be able to cause such a stir, but the power of social media means that negative posts about a company can spread from around the world in seconds.
Subway has always offered footlong sandwiches since it opened in 1965, with customers able to order any filling.
Comments by Facebook users about the photo ranged from outrage to indifference to amusement. One urged people to "chill out". Another man posted a photo of his foot in a sock next to a Subway sandwich to show it was shorter than a "foot".
The Subway footlong photo is the latest in a string of public relations headaches caused by a negative photo or event about a company going viral. Last year, a Burger King employee tweeted a picture of someone standing in trainers on two tubs of uncovered lettuce. And Domino's Pizza employees posted a video on YouTube of workers defacing a pizza in 2009.