A San Francisco 49ers cheerleader took a knee during the national anthem on Thursday in what appears to be the first time a National Football League (NFL) cheerleader has participated in the protest against police brutality and racial injustice launched in 2016 by her team's former quarterback Colin Kaepernick.

While the moment was captured by many on social media—with supporters calling the move "admirable" and "incredible"—the cheerleader has yet to be identified. Since Kaepernick's early protests, multiple football players from other teams and athletes in other sports have joined in the #TakeAKnee movement by locking arms, raising fists, or kneeling as "The Star-Spangled Banner" is played ahead of games.

Several social media supporters noted that kneeling took a great deal of courage, as it could impact her future with the team.

In an article published in October of 2017 titled, "This Is Why NFL Cheerleaders Haven't Taken a Knee," several former cheerleaders told ELLE that "should a cheerleader protest, it would not be taken well by their captains or their teams. Cheerleaders are discouraged from voicing personal opinions while working or critiquing their profession, and when they do, controversy ensues."

Additionally, as the magazine explained, "since cheerleaders are often told how replaceable they are, they felt that they could very easily be fired for taking a stand." In fact, none of the more than 50 current cheerleaders, cheerleader coordinators, and team captains that ELLE contacted would even comment for the article.

As CBS Sports reports:

Although this is the first time an NFL cheerleader has taken a knee, it's not the first time that a cheerleader has done it. At least six cheerleaders at the college level have taken a knee over the past two years. Five of those cheerleaders at Kennesaw State University knelt during the anthem last year. Before that, a dancer at Georgia Tech also took a knee.

Four of the five cheerleaders who protested at KSU didn't make the squad the following year.

While it remains unclear whether the 49ers cheerleader will be penalized for participating, the ultra-rich NFL owners—under pressure from some unsupportive fans and even President Donald Trump—had crafted rules earlier this year to fine football players who join in the anthem protests. However, the NFL halted that policy in July so it could be further negotiated with the players union.