From border towns to the bustling capital, Mexicans are fuming about President Trump's plan to erect a wall between the long-time allies and the threats to use a 20% tariff on Mexican goods to finance it.

As politicians weigh their options, regular Mexicans aren't waiting. Many are taking to social media to get even -- or at least blow off some steam.

Campaigns were launched on social media, urging Mexicans to boycott McDonald's (MCD), Starbucks (SBUX), Coca-Cola (KO) and Walmart (WMT) after Trump signed an executive order for the construction of the wall.

The hashtags #AdiosStarbucks and #AdiosProductosGringos quickly started trending. Starbucks defended itself, saying that its local division is a Mexico-owned franchise which employs some 7,000 Mexicans and features Mexican-grown coffees.

Also many consumers believe boycotts will only hurt Mexicans.

"The (American)companies that operate in Mexico, in reality are Mexican-owned franchises and the workers are Mexican," said shopper Fernando Ruiz, as he walked by one of the many Starbucks shops lining streets in the capital.

Related: Trump wants to 'speed' up NAFTA talks, calls deal a 'catastrophe'

Tensions between the two countries rose after Trump insisted that Mexico pay for the wall and Mexican President Enrique Peña Nieto canceled a meeting with Trump over the standoff.

The Trump's administration then floated the idea of charging a 20% import tax on goods coming from Mexico -- which could generate some $60 billion if you consider that the United States imported some $303 billion from its southern neighbor in 2015.

But trade between Mexico and the United States is incredibly complicated.

Many of the best known American companies that operate in Mexico are locally-owned franchises.

And on the other hand, six million U.S. jobs depend on trade with Mexico. Taxing Mexican imports affects many U.S. companies that send parts south of the border to be assembled.

Related: Here's what else we import from Mexico

About 40% of the parts in a typical Mexican import originate in the United States. For example, before a car arrives at a local dealership, its parts criss-cross the U.S, Mexican and Canadian borders. It's how supply chains are used today.

The biggest concern is Trump's threat to dismantle NAFTA.

Analysts say Peña Nieto has a few cards up his sleeve. For instance, Mexico could stop cooperating on issues like security and drug trafficking.

For now, Peña Nieto is trying to capitalize on a surge in support that he's received thanks to the public feud with Trump. At a press conference in Mexico City on Wednesday, he urged people to buy "Hecho en Mexico" or "Made in Mexico" -- as a response to Trump's "America First".

"We have the capacity to open ourselves to the world, to compete with best and to be the best in the world!"

Related: 40% of a Mexican import is American

Shoppers in the capital's affluent Zona Rosa agreed that it makes more sense to promote Mexican goods and boycotts.

"The trick isn't to boycott, because we're hurting our people," said Susana Gonzalez, another shopper. "We have to produce good things."

And for those who just need to vent their frustrations, there another option: Donald Trump piñatas. Papier mache dolls with his trademark shock of yellow hair and business suits have appeared alongside Batman and Disney princesses.

The only problem is they sell out fast!

"As soon as we get them, they're gone," said shop owner Genoveva de la Cruz, as she displayed the last Trump piñata left at her stall.