Businesses across the city are taking down their signs and awnings because of a mysterious surge in 311 complaints.

The Department of Buildings said that complaints about illegal store signs have more than doubled citywide compared to last year; in Brooklyn, they've tripled. It's not clear what's led to the rise, but Jamie Mauceri, a sign hanger who has combed through the data, has a theory about who the culprit might be. He says the calls often come in batches that target multiple stores on a single block.

"Who else could benefit from it is another licensed sign hanger who could get paid to remove those violations?" he asked. "That could very well be the case."

Whatever the reason, city officials say they need to investigate the 311 complaints when they come in. The city's building code states that signs over six square feet in area, or awnings that extend over a sidewalk, require a permit. And the fines can total $15,000. 

The high fines have lead some businesses to pre-emptively take down their signs, even though they haven't been contacted by the Buildings Department. 

Mo Hauter, whose family owns Triangle Deli in Bedford-Stuyvesant, said the business removed its sign a year ago, after a friend's store in the Bronx was fined $5,000. Hauter said it's a small business and cannot afford a large fine.

“We've been here since the '60s, my family," he said. "They didn't warn nobody about it. They just started giving tickets."

A bill to impose a moratorium on enforcement of the sign law, sponsored by City Councilmember Rafael Espinal, of Brooklyn, is currently on Mayor Bill de Blasio's desk.