San Francisco (CNN) Slammed as unpatriotic and disrespectful, San Francisco 49ers quarterback Colin Kaepernick has taken heat for refusing to stand during the national anthem.

Mother of fallen hero to 49ers QB: Sitting down "easy"

Mother of fallen hero to 49ers QB: Sitting down "easy" 06:10

Mother of fallen hero to 49ers QB: Sitting down "easy"

Kaepernick was criticized as being insulting to those who made sacrifices for the country. A Gold Star mom who lost her son in an IED attack in Afghanistan told CNN that her heart stopped and she lost her breath when Kaepernick said he couldn't stand for the flag. Local war veterans in San Francisco criticized him as a poor role model, according to CNN affiliate KRON. The San Francisco police union has demanded the NFL denounce Kaepernick's "foolish statements."

In another corner, some -- including activists and NBA great Kareem Abdul-Jabbar -- have praised him for bringing awareness to a major issue.

Kaepernick sat in protest over what he called the oppression of black people and people of color, during the national anthem before a NFL preseason game on Friday.

As the controversy grew, members of the military and veterans took to social media using the hashtag #VeteransForKaepernick, which started trending worldwide on Tuesday.

"It's a misconception that every military member is furious at what his protest when there are those that are proud. #veteransforkaepernick" wrote an Instagram user called TreyFade.

I encourage all veterans to make similar post to mine and show support for our brother Kaepernick. Its a misconception that every military member is furious at what his protest when there are those that are proud. #veteransforkaepernick A photo posted by @treyfade on Aug 29, 2016 at 7:01pm PDT

Americans who serve in the military are by no means a monolithic group.

Less than one-third of the US military identify as minorities (Blacks, Asians, American Indian, etc) and 12% are Hispanic, according to a 2014 demographics report of the military community.

Several veterans and service members piped up in defense of Kaepernick.

A man describing himself as an Air Force veteran wrote: "I'm with @Kaepernick7. I'm a vet. I care about people's right to take a stand. It makes us better & smarter."

I'm with @Kaepernick7. I'm a vet. I care about people's right to take a stand. It makes us better & smarter. #VeteransForKaepernick — Charlie (@CharlieInCT) August 31, 2016

Sunny Anderson, Food Network personality and a veteran tweeted: "I took an oath & served, so players on a team I don't even like could have freedom of speech."

I took an oath & served, so players on a team I don't even like could have freedom of speech #VeteransforKaepernick😚 pic.twitter.com/yf7ZWPJvGs — IG SunnyAnderson (@SunnyAnderson) August 31, 2016

Another tweeter listed where his military career had taken him: "West Point, Ranger School, Kosovo, Iraq, Bronze Star. @Kaepernick7 is an American hero."

A woman describing herself as a Navy wife tweeted a picture of her husband who had returned from deployment.

My husband just returned from 8 mos deployment defending @Kaepernick7's freedom of speech. #veteransforkaepernick pic.twitter.com/r4cAmTAAWj — Rebecca Gelinas (@wanderlust5) August 31, 2016

Free speech is free speech, all the time #VeteransForKaepernick pic.twitter.com/tOGOmYe0bC — Coleman Chase (@colemanachase) August 31, 2016

Served from 97-2014 and I'm a firm believer of freedom of speech and expression. #nofilter #VeteransForKaepernick pic.twitter.com/ZDPdmz9xMr — Erica Diggs (@DiggsandCo) August 31, 2016

Don't use my service--or that of any veteran--to justify the silencing of black Americans. Not on my watch. #VeteransForKaepernick — Charles Clymer (@cmclymer) August 31, 2016

I don't agree with all of his points, but I'll fight to the death for his right to say it. #VeteransForKaepernick pic.twitter.com/0jeFlIv5RX — Isaac wright (@I_Zac33) August 31, 2016

Add me to the patriots who support this man and his rights along with his cause #VeteransForKaepernick pic.twitter.com/wVh5o24G4M — Brandon Gericke (@bgericke999) August 31, 2016

I didn't wear all this gear so people could be offended by how others exercise their rights. #VeteransForKaepernick pic.twitter.com/aI1TbxtgyS — Rich Madrid (@rjmadrid) August 31, 2016

Kaepernick has said that his controversial stance is not directed towards people in the military.

"I have great respect for the men and women that have fought for this country," Kaepernick told the press Sunday. "I have family, I have friends that have gone and fought for this country. And they fight for freedom, they fight for the people, they fight for liberty and justice, for everyone."

"That's not happening. People are dying in vain because this country isn't holding their end of the bargain up, as far as giving freedom and justice, liberty to everybody."

The next 49ers preseason game will be played Thursday in San Diego against the Chargers. The Chargers are holding a Salute to the Military game, which is in its 28th annual year. The game gets heavy attendance from service members and veterans.

Deray McKesson, a leader in the Black Lives Matter movement, tweeted a political cartoon juxtaposing Donald Trump saying "America's Not Great" to a crowd of supporters cheering and one showing Kaepernick saying the same thing only to get booed.