In this Sept. 10, 2015 photo, a large gazelle mural...

In this Sept. 10, 2015 photo, a large gazelle mural is shown on the side of a building in the Harlem neighborhood of New York. The mural is one of about half a dozen that have been commissioned as part of a campaign to raise awareness for a nonprofit created by Maziar Bahari, the journalist who spent 118 days in an Iranian jail after an appearance on ?The Daily Show with Jon Stewart. The murals are being painted on buildings around the city as the United Nations General Assembly kicks off Tuesday, Sept. 15. Bahari hopes the art will attract the attention of diplomats and spark a conversation about human rights. (AP Photo/Mike Balsamo) Credit: AP

I'm a nice enough chap, but my cartoons often upset people. The predictable response is some gnashing of molars via email or loudly inscribed snail mail. Some even call to yell at me.

Not my favorite part of the job, but it's fine: Dissonance among grown-ups is normal, healthy and the reason behind free speech. Most of the leaders in the civilized world comprehend that cultures are nourished by this at-times messy and inconvenient process.

Not in Iran.

This summer, 28-year-old artist Atena Farghadani drew a cartoon in response to legislation restricting birth control and the ability of a married woman to initiate a divorce. The drawing depicted Iranian parliamentary leaders with monkey and bull heads -- mild stuff by U.S. or European cartooning standards. She posted it on Facebook and was jailed, and then sentenced to 12 years and 9 months in prison for "insulting members of parliament through paintings."

In other words, she is in prison for doing what I do.

Authorities later accused her of sexual misconduct for shaking the hand of her male defense lawyer. In so doing, the judiciary proved that her cartoon depiction of Iranian authority was accurate.

Farghadani is on a hunger strike, and her mom says she is not well. Amnesty International has declared her a prisoner of conscience and started a petition to appeal for her release.

All because of a cartoon. She is hardly alone: Cartoonists around the world critical of their leaders have met the crushing blow of unsympathetic governments, including:

In April, cartoonist Zulkiflee Anwar Ulhaque, known as Zunar to Malaysians, was charged with sedition for tweets that criticized the judiciary in Kuala Lumpur. He could be sentenced to 43 years in prison if convicted.

Cartoonist and journalist Prageeth Eknaligoda, who supported the opposition candidate in Sri Lanka, was reported missing in 2010. Officials say the investigation is ongoing.

Cartoonist Akram Raslan was taken into custody by agents of the government of Syrian President Bashar Assad. Raslan, who was detained at his newspaper's offices in 2012, has been reported dead by the state's own news service. He reportedly died in a jail hospital in 2013.

Cartoonists Bahadir Baruter and Ozer Aydogan of the Turkish satirical magazine Penguen were found guilty of insulting Turkey President Recep Tayyip Erdogan. They were sentenced to 14 months in prison. That sentence was reduced to 11 months for "good conduct" during the trial, and subsequently commuted to a fine.

Ecuadorean cartoonist Xavier Bonilla, known artistically as Bonil, has been the repeated target of government prosecution -- sued by the president and reprimanded by congress -- most recently earlier this year over a drawing of a stuttering local politician.

In Farghadani's case, a state has used a supposed legal system as a weapon to silence a satirical voice deemed dangerous to the regime. A quiet, rigged trial in Iran isn't spectacular enough to spur crowds to chant in Western streets.

I've been able to cartoon, for example, in favor of the Iran nuclear deal because open societies allow the free flow of ideas as a vital part in the tolerance of oppositional thought. Iran has a young, sophisticated populace, and one day it may be more tolerant of the opposition, but I do harbor reservations about the fearsome nature of the men who rule in Tehran.

Iran's leaders should realize that by stamping out their citizens' ability to speak, they show that what scares them most is not a nuclear exchange, but an exchange of ideas.

And a courageous young woman sits in jail for the crime of pointing that out.

Matt Davies is a Pulitzer-winning cartoonist for Newsday.