The United States has an "undeniable problem" with structural racism, the activist movement Black Lives Matter said following NFL quarterback Colin Kaepernick's protest against racial discrimination.

Kaepernick staged his silent protest last week when he refused to stand for the national anthem before an NFL game, protesting about police killings of unarmed black men in a country that "oppresses black people and people of colour".

Kaepernick was backed by his team, the San Francisco 49ers, but faced a barrage of abuse and criticism, including a comment from US presidential hopeful Donald Trump who, brushing aside the issue of racism, told him to "find a country that works better for him".

But Opal Tometi, cofounder of Black Lives Matter, said ignoring the wider issue of racism is naive.

"Some people are ignorant or choose to hide behind their privilege and profess that racism isn't an issue," Tometi told Al Jazeera.

"But this is naive, disingenuous and lacks a genuine look at the facts and countless stories that say racism is alive and well in the US. It is undeniable that there is systematic oppression of people of colour in the US."

Smart move by Kaepernick to get conversation away from fact he gets worse every time he plays football — Ross Tucker (@RossTuckerNFL) August 27, 2016

According to a study done last year, young black men were nine times more likely to be killed by police officers compared with other Americans.

While non-white Americans made up only 37 percent of the US population, more than 47 percent of all people killed by police belonged to a minority.

Another survey revealed the African Americans were three times more likely to be searched (person or vehicle) than whites.

"We can already see the backlash that Kaepernick is receiving from hate mail, death threats, and people burning his jersey and effigy," Tometi added.

"Also other players who were trying to follow his lead are being bullied into submission by white elites in power. We see widespread efforts to silence their voices. It's disturbing, unethical and anti-democratic."

Reminders

Kaepernick is not the first athlete to speak out against racial discrimination in the US, but his actions did attract criticism from former athletes, including former Pittsburgh Steelers' Hines Ward, who did not "agree with the method he chose".

"If you want to make a point or take a stand, go straight after the root of that cause," said Ward. "Don't disrespect the whole country or the organisation that's paying you millions of dollars."

@Kaepernick7 There's ways to make change w/o disrespecting & bringing shame to the very country & family who afforded you so many blessings. — Heidi Russo (@Heidirn1) August 27, 2016

Kaepernick did, however, find an ally in Kareem Abdul-Jabbar, the NBA's all-time leading scorer, who came to his defence recently and called the NFL player's actions "highly patriotic".

"What should horrify Americans is not Kaepernick's choice to remain seated during the national anthem, but that nearly 50 years after Ali was banned from boxing for his stance, and Tommie Smith and John Carlos's raised fists caused public ostracisation and numerous death threats, we still need to call attention to the same racial inequities," he wrote in a recent article .

"Failure to fix this problem is what's really un-American here."

Olympic runners Tommie Smith and John Carlos held up their fists in a black power salute during a medals ceremony in 1968.

In December 2014, St Louis Rams players entered the stadium for a home NFL game with their hands raised, a reference to the "Hands Up, Don't Shoot" slogan adopted by protesters in demonstrations against the shooting of an unarmed black teenager in Ferguson, Missouri two years ago.

'Encourage positive change'

Alicia Strong, an activist, did not agree with Kaepernick's method of protest either, but told Al Jazeera that the quarterback was correct in speaking out and not staying silent.

"I think more athletes and celebrities should use their fame to encourage positive change," Strong said.

"I am assuming he wanted to do something that would get him the publicity he needed to spread his message. It worked. However, I disagree with this method because I feel in some ways his message is getting lost.

"What he did was controversial and offensive to many. This is taking away from his message as the focus has shifted towards discussing the validity of sitting down for the anthem as opposed to racial inequity in the US."

In July, thousands protested across the US over police killings of black men for five straight days.

US President Barack Obama called it a "very tough week", in which Alton Sterling, a 37-year-old father of five, was killed by white police officers in Louisiana.

His death was followed the day after by the police killing in Minnesota of Philando Castile, a young black man who worked at a local school serving food to children.

Castile's death was filmed by girlfriend Diamond Reynolds and streamed live on Facebook.

Kaepernick may not remain a 49er for too long in the future. However, the voicing of his opinion does mean that he wants to make the country better, according to Strong.

"People in the US need to start listening to each other more," Strong added.

"On the subject of police brutality, bridges need to be built between police forces and the communities they serve. Society can't function properly if people of colour are perceived as threatening and officers are perceived as dangerous.

"If every person who saw a fault in our country simply left, who would remain to truly make our country great?"

Follow Faras Ghani on Twitter: @farasG