More than 2 million protesters in 436 cities across the world took to the streets Saturday, in a unified charge against agribusiness giant Monsanto and genetically modified foods. The AP reported that the "March Against Monsanto" protests took place in at least 52 countries and 436 cities.

The movement grew from a Facebook page — reportedly created months ago — that called for the May 25 demonstrations. The organizers advocate for boycotts against Monsanto-owned companies that use GMOs (genetically modified organisms) and pushed for GMO labeling, in addition to further studies of the health effects of GMOs.

Genetically modified organisms have been engineered with ideal traits. Monsanto, which ranked #206 in 2013's Fortune 500 list, is a large producer of genetically modified seeds.

In the U.S., the Food and Drug Administration (FDA) supports voluntary labeling for foods produced via genetic engineering. This year, President Barack Obama signed a bill that included a "Farmer Assurance Provision," which reportedly could make it more difficult to stop the sale of questionable crops. That's why critics nicknamed it the "Monsanto Protection Act."

On Thursday, the U.S. Senate also voted against a measure that would have let states decide if they wanted to require labeling for GMOs, The Huffington Post reported.

& this is why i did the protest yesterday, for the future of kids like him. #monsanto #marchagainstmonsanto twitter.com/angieelombardo… — angelica ૐ (@angieelombardo) May 26, 2013

I'm at my first protest ever. I don't even begin to understand how Monsanto gets away with it. Lets make sure our food is FOOD. — Nicole Glaros (@nglaros) May 25, 2013

Among Saturday's online chatter about the protests, Monsanto remained active online through its social media efforts. Most of the St. Louis, Mo.-based company's tweets were marked with the hashtag #Monsanto. On the company's official Facebook page, a link to what its employees stand for was also posted.

What #Monsanto Employees Stand For – new post at Beyond the Rows monsantoblog.com/?p=6846 — Monsanto Company (@MonsantoCo) May 25, 2013

#Monsanto Named One of CR Magazine's 100 Best Corporate Citizens bit.ly/116ZcXy — Monsanto Company (@MonsantoCo) May 25, 2013

Thumbnail and lead image courtesy of Flickr, John Novotny.