In Tabasco state on the Gulf of Mexico, a law is expected to go into effect this week that mandates a jail term of up to two years for those who "provoke chaos or social insecurity" through telephone calls or online postings.

Its enactment would come days after a prosecutor in neighboring Veracruz state tossed two people - a math tutor and a grandmother - in jail on terrorism and sabotage charges for their tweets.

The two face 30 years or longer in prison if convicted.

The legal moves are the latest in what amounts to a war over information - or lack of it - in areas of Mexico convulsed by criminal turmoil.

In many of those areas, traditional media have sharply limited what they report for fear of reprisals from mobsters or because they worry that state advertising will be cut off.

That's sent Mexicans to social media, where they keep one another informed of shootouts, roadblocks, beheadings and other criminal acts, and to offer opinions about their elected leaders' inability to stop the violence.

"I dare to say that a majority of narco-related violence is not actually reported (in traditional media)," said John M. Ackerman, a legal scholar and columnist. That leaves Mexicans hungry for news. "They want to know in order to take care of themselves, their personal security."

Ackerman said provincial governors "are really sort of like feudal lords in Mexico," and they view information about crime as a potential threat to political control.

A Tabasco legislator, Jose Espinoza May, rejected that view, saying the pending law is to deter people from recklessly spreading falsehoods.

"It's not a gag law nor is it an effort to stifle freedom of expression. Rather, it's so that we rise to the needs of a new Tabasco ... (to battle) alterations of social peace," Espinoza told El Informativo, a newscast in Villahermosa, the state capital.

The modification to the penal code in Tabasco was approved Aug. 27 by the state's 35 legislators and now awaits publication in the official newspaper, said Rubi de la Cruz, who works for the state legislature. "I think that will happen (this) week," she added.

The need to keep the peace was also cited in the case of Gilberto Martinez (gilius22), and Maria de Jesus Bravo (maruchibravo) in Veracruz state.

The two are in jail for tweets they posted on Aug. 25 saying that drug cartel gunmen had attacked a school and killed children in the Boca del Rio district of Veracruz.

The state's public security chief, Gerardo Buganza, said the reports - which authorities say were untrue - caused "more than 26 accidents" as panic-stricken parents rushed to retrieve children.

The lawyer for the two, Felipe Ordonez Solana, said his clients simply tweeted what already had been circulating on the Internet for several hours. He disputed Buganza's allegation of resulting chaos, saying no reports of multiple accidents appeared in the city's newspapers the next day.

"They are scapegoats ... so that all of us Veracruzanos do not say bad things about our distinguished governor. I hope you capture my satire," Ordonez said in a telephone interview.

But Gov. Javier Duarte defended the arrests, ironically in a tweet to his 45,500 followers: "I am a heartfelt Twitter user, I am in favor of freedom of expression but I defend our right to live in peace and tranquility."

Lawyers and advocates, however, warn that the backlash against social media strikes at basic rights.

"The government wants to control information through these laws," said Roberto Arrucha, a lawyer and founder of an advocacy group, the Twitter Contingent of Veracruz. He said that as criminal turmoil worsens, state officials routinely "make up statistics, hold information back and hide violent events."

Arrucha said the efforts to put limits on users of the Twitter micro-blogging service, which limits posts to 140 characters, and Facebook will not halt the use of social media.

"People are already going to anonymous accounts. They are protecting themselves. There is a proliferation of anonymous users now," Arrucha said.

Ackerman said efforts to penalize users of social media for spreading unconfirmed reports "will be completely counterproductive" as more Mexicans hide their identities online.

"It will make it even easier for people to spread rumors," he said.

The use - or misuse - of social networks is an issue winding up in courts worldwide. Last month, two British men were sentenced to four years in prison each for inciting violence on their Facebook pages during London riots.

In early August, California legislators passed a law that threatens jurors with prison time if they tweet, blog or otherwise use the Internet to divulge information or opinions about the trials they are hearing.

Venezuelan authorities charged two people with using tweets to urge people to pull money out of banks in July 2010 in an effort to spark a run on the financial system. They could get up to 11 years in prison if convicted.