A sign alongside the Pemex headquarters reads "Pemex more united." (Alfredo Estrella/AFP/Getty Images)

Mexican President Enrique Peña Nieto unveiled an historic proposal on Monday to allow foreign firms to invest in Mexico's massive energy sector, which has been dominated since the 1930s by the state-owned firm Pemex.

Peña Nieto's plan could potentially revolutionize the Mexican oil and gas industry, which has been notoriously sluggish but remains a crucial component of the country's economy. Still, it would mean allowing foreign oil giants such as Exxon Mobil or Shell a toehold in Mexico's energy market, which is about the size of Kuwait's. And that's generated some real controversy.

Within Mexican media and social media, people are debating whether this move will ultimately help Mexico by revitalizing the troubled energy sector or if it will risk allowing foreign firms to siphon off wealth that should belong to Mexicans. Global Voices, which covers online discussions around the world, has rounded up some of the most prevalent arguments on both sides in a post by writers J. Tadeo and Tiago Miller. Here's some of what they found and translated into English.

Mexicans opposed to the reforms worry that it may be a step toward privatizing Pemex or the entire Mexican energy sector outright, something Peña Nieto pledges not to do. John M. Ackerman, a prominent Mexican law professor and columnist aligned with the political opposition, argued that the proposal "exposes the gross ambition of big national and foreign companies to get themselves an even larger slice of the national wealth." He disputed what he characterized as the pro-reform view that "greater 'involvement' by Exxon-Mobil and Halliburton will automatically benefit the Mexican people." Ackerman's view seems to be a common one among those opposed to the plan.

Those advocating for Peña Nieto's reforms seem to see opportunity for Mexico in an underperforming state enterprise. Miguel Carbonell, a researcher at Mexico's Institute for Legal Research who has a huge social media following, tweeted "50% of the oil that we consume in Mexico we have to import. We’re doing something wrong." He used the hashtag #reformaenergetica, which some Mexican Twitter users have adopted to show their support.

Many supporters of the plan, according to Global Voices, argue that Mexico might be able to follow the example of Norway, which has been a huge – and highly unusual – success story in spreading energy wealth widely, equitably and sustainably. They quote economics professor Luis Pazos, who tweeted, "In Norway, with private partners in state owned petrol companies and less employees than PEMEX, they produce more."

The debate over reforming Pemex is still going – and, as Peña Nieto pushes through the changes, which are expected to pass, that debate will only continue.