(CNN) -- A pair of Florida men and their female friend are experiencing a backlash over their controversial Halloween costumes after a picture of them went viral online over the weekend.

The two men in the picture, whom we will not name here, appear to be at a Halloween gathering dressed as Trayvon Martin and George Zimmerman -- two central figures in one of the year's most high-profile court cases. Martin, 17, was shot and killed by Zimmerman in Florida in February 2012. Zimmerman, a leader of his neighborhood watch, claimed self-defense and was acquitted of the teen's murder in July.

In the photograph, the man on the left is wearing a gray hoodie stained with fake blood and what appears to be a black mask or black face paint. The man on the right is wearing a shirt that bears the words "Neighborhood Watch," and his fingers -- simulating a gun shape -- are pointed at the first man's head.

The photo, posted by the woman standing between them, was shared on Facebook and Instagram on Saturday with the caption, "Happy Halloween from Zimmerman and trayvon :)"

The picture was picked up by website The Smoking Gun and other outlets, including several CNN iReporters who sent in screenshots, some saying the costumes took the spirit of Halloween "too far."

"As a nation that claims to be so full of diversity and unity, race is still a raging issue," wrote one iReporter. "So I ask when you look at this photo that you put race a side [sic], and focus on the lack of respect for not only human life but a child's life."

The picture has inspired anger for two reasons: First, because the costumes portray a tragedy. News One claims the stunt "revictimizes" Martin. A Chicago Now blogger questioned the intent of the costumes: "I further wonder why they feel that the tragic death of a teenage boy deserves to be mocked in such a nonchalant manner?"

Another reason people are so disturbed by the costumes is the use of "blackface" in one of the costumes. Blackface, a term used when a non-black person paints their face a darker color, has a long history of being considered offensive, even when the intent isn't specifically to ridicule or shame.

Actress Julianne Hough was criticized recently after stepping out at a Halloween party in blackface to portray a character from the show "Orange is the New Black."

Hough was chastised on Twitter, and eventually apologized. "It certainly was never my intention to be disrespectful or demeaning to anyone in any way. I realize my costume hurt and offended people and I truly apologize," Hough tweeted in response to the controversy.

The Utah Jazz also tweeted out a picture Sunday night of two young men, one of whom was dressed as famous power-forward Karl Malone -- complete with blackface. Soon after, the team erased the tweet and apologized for the "insensitive" post.

The outrage sparked by the Martin-Zimmerman costumes has inspired acts of retribution. Posters on several websites have dug in to the identities of the three people in the picture and posted personal information about them, including their phone numbers, arrest records and past activity on social media.

Since the photo gained attention, the three individuals in question have made their Facebook accounts private and the picture itself appears to be scrubbed from their profiles.