“Avoid Plaza Las Américas,” several people wrote, giving the location.
“There are gunmen,” wrote others, adding, “they’re not soldiers or marines, their faces are masked.”
These witness accounts have become common in Mexico over the past year, especially in violent cities where the news media have been compromised by corruption or killings. But the flurry of Twitter messages about the bodies arrived at a telling moment — on the same day that Veracruz’s State Assembly made it a crime to use Twitter and other social networks to undermine public order.
It is the first law of its kind in Mexico, but most likely not the last. At least one other state, Tabasco, is considering a similar measure, and all across Mexico, public officials are now complaining about new technologies that can help spread rumors. Panic is the fear: Two people in Veracruz were charged last month with terrorism and sabotage after their Twitter messages — spreading a false rumor that schools were under attack — seemed to cause traffic accidents as parents flooded the roads.
And yet, according to scholars and many Mexicans, social media has become a necessity in Mexico, with a mission far different from what has emerged in the Arab revolutions, or in China. In those countries, social networks have been used to route around identifiable sources of repression and to unify groups dispersed over large areas. In Mexico, Twitter, Facebook and other tools are instead deployed for local survival.
“These aren’t acts of political sedition or real-time attempts to bring about a change in government,” said Nicholas T. Goodbody, a professor of Mexican cultural studies at Williams College. “These are people trying to navigate daily life.”
In many ways, the explosion of electronic crime-sharing is the product of trends that both create and destroy communities: Mexico today is both highly connected and highly dangerous. Around 40,000 people have been killed in the ramped-up drug war of the past five years, while the middle class is growing, scared and increasingly networked. Cellphones are as common as keys; Twitter has more than four million users in Mexico, according to tracking companies; and among the more than 30 million people with regular Internet access, 95 percent have profiles on Facebook.
Add to that the proliferation of Web sites and blogs dedicated to covering violence with submissions from readers (Wikinarco, Blogdelnarco, Borderland Beat), and what Mexico has ended up with is a crowd-sourced universe of morbid, frightening information — which is often not available elsewhere.
“Social media is filling the gap left by the press,” said Andrés Monroy-Hernández, a doctoral candidate from Mexico at the M.I.T. Media Lab. “In different regions of Mexico, both the state and the press are weak, while organized crime is becoming stronger and, in some places, replacing the state.”
Many Mexicans now say they trust Twitter more than local news outlets, and in some areas, parents and grandparents are being taught by their children how to get online — specifically so they can be safe.
Anonieta Salazar Loftin, a doctoral student in Mexican history at the University of Texas at Dallas, said this is how her relatives back home use social media. She said that anonymous crime-focused Twitter accounts like @balaceramty — which is based in Monterrey and has more than 40,000 followers — provide a needed public service.
“They fulfill the need for information in an immediate and accessible way and, on a deeper, psychological level, provide some knowledge or certainty in the face of uncertainty,” Ms. Loftin said.
The Veracruz law is specifically aimed at false rumors that create unnecessary panic. But experts say that given how hazy real-time reports of violence can be, there could also be a danger of prosecuting well-intentioned watchdogs who share information that turns out to be wrong.
Diana (a k a @mariana_war), one of many Mexicans who is following developments in Veracruz via Twitter, said that more good than bad comes from open, unregulated sharing. Declining to give her full name out of fear, she said that while she probably lives with more fear now because she is “in the know” thanks to social media, its civic role should not be undervalued.
Referring to digital warnings about cartel checkpoints and shootouts, she said, “People’s lives are saved with Twitter.”
Not always. Two weeks ago, a man and a woman in their early 20s were found hanging from a bridge in the border city of Nuevo Laredo, with a sign near their mangled bodies that read: “This will happen to all the Internet snitches.” A third person was found dead on Saturday with a sign declaring she was killed for social media postings.
These are grisly warnings to the new media faithful. “Social media is no longer for fun and socializing in Mexico,” said a contributor to Borderland Beat from the state of Tamaulipas, who goes by @OVEMEX.
The killings highlighted the growing power of the so-called cyber guardians, whose Twitter accounts sometimes carry avatars depicting Pancho Villa and other heroes of the Mexican Revolution. The drug cartels, which have often successfully enforced information blackouts at the local level by intimidating the police and reporters, are clearly threatened by the decentralized distribution of the Web. And it may be harder for them to control.
“People are uniting and exposing the truth,” said @OVEMEX, pointing out that delicate information often passes through several people or accounts before it reaches the public. “We all watch each other’s backs.”
Of course, Mexico’s struggle goes well beyond information. Mr. Monroy-Hernández at M.I.T. said that the spread of social media, which he describes as a symptom of institutional dysfunction, will probably not “play a central role in fighting the problem.”
Some government officials may figure out how to work with, or at least tolerate, social media. On Wednesday afternoon in Veracruz, the authorities said they had identified most of the 35 dumped bodies, which were discarded, seminude, near a mall popular with tourists. They said that 12 were women and that nearly all of the identified victims had criminal records, hinting that they may have been members of the Zetas gang, killed by rivals.
On Thursday, an additional 11 bodies turned up across the city, prompting another round of Twitter commentary.
But by that time, the state’s governor, Javier Duarte de Ochoa, had pardoned the two Twitter users who had sent out false messages about the attacks against local schools. He even announced it on Twitter.
Online, the response was swift. “He’s not useless after all,” wrote one Mexican Twitter user.
Another, referring to a Twitter campaign of solidarity with users using #TwitTerrorista in their messages, added: “Thanks to our efforts, our Twitter friends are free.”
Karla Zabludovsky contributed reporting.
This article has been revised to reflect the following correction:
Correction: September 25, 2011
An earlier version of this story misstated the given name of a doctoral student in Mexican history at the University of Texas at Dallas. Her name is Anonieta Salazar Loftin, not Antonio.
