The Green Party is planning on keeping the posters up for months
Billboards can reveal a lot about a country.
They tend to show what advertising executives and politicians think are the desires and fears of the people they target.
The skyline of Mexico City is a case in point.
It is dominated by the usual alluring, aspirational adverts for products like Bacardi rum, cheaply financed cars and lipstick.
But scattered among them are huge black posters calling for the reintroduction of capital punishment.
"Because we care about your life - death penalty for murderers and kidnappers," they demand in bold yellow letters.
The campaign, somewhat incongruously, is paid for by Mexico's Green Party. The organisation's mascot, a large toucan against a green backdrop, appears prominently on each poster.
Blighted by crime
The contrasting messages on the city's billboards highlight one of the idiosyncrasies of this country.
While its GDP puts it among the richest 15 countries in the world, its official kidnapping rate tops that of Iraq.
Moreover, murders linked to organised crime - in particular the drugs trade - are soaring with almost 6,000 people killed last year, double the number for 2007.
Children are being murdered and kidnapped, the current policy is not working
Gloria Lavara Mexican Green Party
It is against this background that Mexico's tiny Green Party has decided to campaign for the reintroduction of the death penalty.
It has been almost 50 years since anyone was executed in Mexico. A soldier was the last person to face a firing squad in 1961 for insubordination and murder.
In 2005, Congress abolished the death penalty and removed all references to it from the constitution.
Antonio Garcia, a senator campaigning against capital punishment at the time, called it "the most cruel, inhumane and degrading punishment, and a violation of the right to life".
'The voice of the people'
However, Gloria Lavara, the Green Party deputy who is coordinating the pro-capital punishment campaign, makes no apology for shifting the main focus of her party from protecting the environment to endorsing a policy which the Green movement worldwide rejects.
"We are expressing the voice of the people," she says.
If people do not respect the lives of others, then they too have lost the right to life
Elvia Mexico City resident
"Children are being murdered and kidnapped, the current policy is not working."
But according to Juan Francisco Torres Landa, a lawyer who represents Mexico United - a non-governmental organisation campaigning against crime - there is no evidence that the death penalty acts as a deterrent to criminals.
"I believe the Green Party is promoting a media campaign simply to obtain political dividends," he says.
But a random straw poll of people in a Mexico City shopping centre seems to lend some support to Ms Lavara's views.
Everyone I spoke to favoured the reintroduction of the death penalty.
"If people do not respect the lives of others, then they too have lost the right to life," said one middle-aged woman who gave her name only as Elvia.
Another woman said she had her own reasons for strongly believing that kidnappers should be executed.
"I was kidnapped for two hours," she said. "They hit me, and molested me. They even threatened to rape me."
Alejandro Marti, whose son was kidnapped and murdered, on crime in Mexico
Nevertheless, the chances of capital punishment actually being reinstated in Mexico are extremely remote.
President Felipe Calderon's National Action Party (Pan) and the leftist PRD both oppose it, as does the Roman Catholic Church.
The PRI, the party which held power in Mexico continuously for more than 70 years until 2000 supports public debate on the issue.
Late last month, Congress voted to consult on the issue.
It promised to host forums, bringing together opinion from all sides of the debate. The outcome will not be legally binding.
The Green Party posters are expected to remain in place for months - a daily reminder of the violence which millions of Mexicans dread, and simply want to end.
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