President Barack Obama has expressed serious concerns about the spread of fake news on social media platforms such as Facebook during the election season, arguing that people have started believing "outright lies" and "crazy stuff" as normal so long as it is on social media.

Speaking at a rally for Hillary Clinton in Ann Arbor, Michigan on Monday, Obama said he has been frustrated with the coverage this election, adding that a lot of it has not been "on the level."

"The way campaigns have unfolded, we just start accepting crazy stuff as normal and people if they just repeat attacks enough and outright lies over and over again," Obama said. "As long as it's on Facebook, and people can see it, as long as it's on social media, people start believing it, and it creates this dust cloud of nonsense."

Over the past weekend, a fake news story titled, "FBI agent suspected in Hillary email leaks found dead in apparent murder-suicide" by a phony website dubbing itself the "Denver Guardian" began to spread on the social media platform.

The circulation of fake news on Facebook has been an ongoing issue and source of criticism for the social media giant in recent months. To improve its trending news section, Facebook fired its human "news curators" in August and decided to opt for a more "algorithmically driven process" to decide which stories will be included in the Trending box, based on its importance and popularity. However, a series of conspiracy theories and fake news stories soon started to slip past the company's algorithm.

The company responded by putting together a "review team" to work on its Trending news feature, but who have less editorial control than the previous news editors.

In September, Facebook and Twitter announced they would join a coalition of more than 30 news and tech companies to combat fake news on their platforms and educate users about news sources.

However, a recent BuzzFeed investigation found that 38% of posts shared by three popular right-wing pages on Facebook were "either a mixture of true and false or mostly false," as compared to 19% of posts from three hyperpartisan left-wing pages that did the same thing.

Another investigation conducted by BuzzFeed found that nearly 140 fake US politics websites have been launched by teenagers in Macedonia, such as, and among others, almost all of which aggressively post misleading, pro-Trump content catering to Donald Trump supporters and conservatives.

On Facebook, these sites' 'official' pages sport hundreds of thousands of followers, BuzzFeed reports.

"I started the site for an easy way to make money," an unidentified 17-year-old from Macedonia who runs with four others said. "In Macedonia, the economy is very weak and teenagers are not allowed to work, so we need to find creative ways to make some money. I'm a musician but I can't afford music gear. Here in Macedonia, the revenue from a small site is enough to afford many things."

Although users are increasingly turning to social media platforms such as Facebook as their source of daily news, Facebook has continued to maintain that it is a technology company and not a publisher or a media company.

In September, Facebook chief executive Mark Zuckerberg said that the company does not have any plans to become a media company.

"We are a tech company, not a media company, Zuckerberg said, Reuters reports, adding that as a "technology company, we build the tools, we do not produce the content.

"The world needs news companies, but also technology platforms, like what we do, and we take our role in this very seriously."