Smith's May summons landed him in court. Court records indicate he pleaded guilty on Aug. 22, 2012, to the disorderly conduct charge and agreed "to curb disorderly behavior (loud whistling) in the future."
The plea agreement prohibits Smith from standing in one place and whistling. As long as he whistles while he walks, authorities agreed not to bother him.
His legal troubles are not enough to keep him from his passion.
Smith said he told police: "You can arrest me a thousand times, and the day I walk out of this jail, I'll be whistling out the door."
The reactions to his whistling have more to do with the listeners than the whistling itself, Smith said. While some smile, others confront him and threaten to beat him up, he said.
His whistling is such a shared experience among downtown regulars and office workers that he pops up in blog posts and online conversations.
"He acts like he's treating all of us to his amazing whistling show and that we should all be so lucky to hear him and his magical ability, but I don't feel lucky," wrote one blogger in a 2011 post to Thought Catalog. "I feel deep anger and hatred, because his whistling upsets my dog and every dog in the neighborhood."
People often speculate that Smith's whistling carries an ulterior motive. But despite being arrested four times in his life, there is no proof of such claims. He has been convicted of misdemeanors including theft, assault and harassment by telephone.
"I've heard that drug (dealing) thing. It doesn't faze me one bit," he said. "They just want an answer to what I do every day. They want to put an answer to something they have no answer to."
Smith said he unsuccessfully argued with police that the constitutional right to free speech protects his right to whistle.
"All I'm doing is expressing myself freely," he said recently. "People who express themselves freely should be held in the highest regard, not the lowest regard."
The American Civil Liberties Union of Maine declined to comment on Smith's specific case. However, the free-speech advocates said in a written statement that punishing someone for whistling does raise First Amendment concerns.
"In general, merely being annoying isn't enough to constitute disorderly conduct," said Maine ACLU spokeswoman Rachel Healy. "Unless it's meant to incite chaos or violence, whistling in public is usually not a crime -- and punishing someone for it could raise real First Amendment concerns."
McAllister, the city prosecutor, said she disagrees that whistling is a protected form of free speech.
A Portland city ordinance specifically mentions whistling as a disorderly behavior, which carries fines ranging from $100 to $500.
Since at least 1993, whistling has been included in the disorderly conduct ordinance, along with hooting and other unnecessary noises that "either annoy, disturb, or injure the health, peace or safety of others."
The code prohibits "the use of any loudspeaker or amplifier for the purpose of commercial advertising or attraction of the public to a specific building, location or business, yelling, shouting, hooting, whistling, or singing shall be considered to be loud, disturbing, and unnecessary noises."
According to McAllister, Smith's whistling fit the bill.
"The judge and I viewed this as a behavioral issue," she said. "(The Whistler) was aggressive. He would follow people who gave him a wrong look."
FAMOUS OR INFAMOUS?
The Whistler is no stranger to many Portland residents or workers.
"I do see him a lot," said Greta Bank, an artist who leases studio space on Congress Street. "Everybody does."
Bank and her husband, Scott Peterman, a fellow artist and photography instructor at the Maine College of Art, incorporated The Whistler's likeness in a window display last fall at the Space Gallery.
The display -- "Godzilla Attacks" -- included a model of downtown Portland that was used to make a Godzilla parody film. The display was about 2 feet tall, Bank said, and The Whistler, who was depicted wearing a New York Yankees hat and his backpack, stood about 8 inches. Bank said he is nearly as much of a fixture downtown as the buildings themselves, and there is no conceptual linkage between The Whistler and Godzilla.