Brandon Stanton is an advocate of allowing people to speak their minds. On Monday, the man behind the popular website, Humans of New York, decided to speak out in a blunt open letter to Donald Trump.

"Along with millions of Americans, I’ve come to realize that opposing you is no longer a political decision. It is a moral one," Stanton wrote in a powerful letter, which was posted to the HONY Facebook page and his personal Twitter account.

The post comes in the wake of a weekend that saw violence in Chicago, where Trump supporters clashed with protesters after the candidate was forced to cancel a rally. Trump took no responsibility for the incident and instead blamed Democratic presidential candidate Bernie Sanders and his supporters for the riots, and threatened the Vermont senator by tweeting:

Bernie Sanders is lying when he says his disruptors aren't told to go to my events. Be careful Bernie, or my supporters will go to yours! — Donald J. Trump (@realDonaldTrump) March 13, 2016

In his letter, Stanton criticizes Trump for inciting violence at his rallies and promoting hateful ideologies toward Muslims, refugees and immigrants, writing:

I am a journalist, Mr. Trump. And over the last two years I have conducted extensive interviews with hundreds of Muslims, chosen at random, on the streets of Iran, Iraq and Pakistan. I’ve also interviewed hundreds of Syrian and Iraqi refugees across seven different countries. And I can confirm— the hateful one is you.

Merry Christmas! Yesterday we raised nearly $500,000 in financial assistance for the refugee families we met during the... Posted by Humans of New York on Friday, December 25, 2015

Trump has also made polarizing comments about people with disabilities, Jewish people, women and black people:

Our great African American President hasn't exactly had a positive impact on the thugs who are so happily and openly destroying Baltimore! — Donald J. Trump (@realDonaldTrump) April 28, 2015

Stanton's comments have apparently struck a chord. In the first four hours since it was posted, the message has received over 900,000 likes and 500,000 shares.

To read it in full, see below:

An Open Letter to Donald Trump:Mr. Trump,I try my hardest not to be political. I’ve refused to interview several of... Posted by Humans of New York on Monday, March 14, 2016

Editor's Note: Donald Trump is a serial liar, rampant xenophobe, racist, misogynist, birther and bully who has repeatedly pledged to ban all Muslims -- 1.6 billion members of an entire religion -- from entering the U.S.