Boxers do it. Bombers do it. Even vice presidential candidates do it.

But while the ranks of hoodie wearers are legion, the hooded sweatshirts worn by everyone from Rocky Balboa to Ted Kaczynski to Sarah Palin suffer an identity crisis. Is it a source of casual comfort, a criminal's cloak or as recent protests over the death of Florida teen Trayvon Martin would suggest, a symbol of social injustice?

The answer, it seems, depends on the wearer.

Martin, 17,  was wearing a hoodie when he was shot and killed by George Zimmerman in February. Police said Martin was unarmed, carrying a bag of candy and iced tea as he returned to a gated community in Sanford, Fla. Zimmerman, who called in a suspicious person complaint to local police, claims he was acting in self-defense and has not been charged in the case.

A public outcry over the handling of the case has led people to act:

  • Several local churches held "Hoodie Sunday" services at which attendees wore hoodies in support of Martin and his family.
  • Million Hoodie Marches cropped up in cities around the country.
  • Members of the Miami Heat, as well as other celebrities, tweeted images of themselves wearing hoodies.
  • Politicians wore hoodies to work, including Rep. Bobby Rush, D-Ill., who was escorted from the House floor Wednesday for violating the dress code.

Meanwhile, Fox News Channel commentator Geraldo Rivera apologized Tuesday for using language suggesting that Martin's hoodie was as much a factor in his death as Zimmerman wielding a gun.

The Martin case may have put hoodies in the hot seat, but the ubiquitous garments already had a sullied history.

"They have taken on a significance that for whatever reason is associated with something bad," said Deirdre Oakley, associate professor of sociology at Georgia State University who noted that students of all types wear hoodies on campus. "This is reflective of negative sentiments toward the youth culture, and it gets exaggerated based on the person's race and the person’s gender."

A lot of criminals do wear hoodies, but then so do a lot of celebrities. Hoods provide an easy cover for anyone hoping to obscure his or her identity. One of the most well-known hoodie-wearing criminals is Ted Kaczynski, the "Unabomber," who appeared in a much circulated forensic sketch wearing dark classes and a hoodie. Kaczynski is serving life in prison without parole for a 20-year mail bombing campaign.

When hooded garments first surfaced in ancient Rome, they were purely functional, said Sarah Collins, associate chairwoman of fashion at SCAD Atlanta. "Hoods were for protection from the environment," she said.

Then in the late Middle Ages, hoods took a turn. "They added extensions to the hoods that were purely decorative," Collins said. The hood had begun to shift from protective garment to style statement.

In the early 20th century, hoodies became a sportswear staple worn solo or as one-half of a track suit.

As the decades wore on, they popped up in less expected places -- as part of punk culture in the 1970s and as a costume worn by the fictional Rocky Balboa in the 1976 movie about a working-class boxer. In the 1980s, hip-hop culture, both real and fictionalized, co-opted the hoodie, which has been worn by rappers ranging from Ice Cube to Vanilla Ice. And last year, former vice presidential candidate Sarah Palin posed for the cover of Newsweek in a gray button-up hoodie.

Hoodies don't discriminate, but people do. And Americans are a little behind in our hoodie hang-up. British politicians singled out the garment years ago for its mixed message. While former Prime Minister Tony Blair supported banning hoodies in public, current Prime Minister David Cameron called for hoodie understanding, making the point that wearing a hoodie is a way for British youths to become invisible in a dangerous environment.

But Martin supporters argue that a black male wearing a hoodie is more marked man than mystery man.

"When it is worn by black men ... it becomes a garment that is the equivalent of a mask worn by someone who is probably up to no good," said Nathan McCall, a lecturer at Emory University who teaches a course on African-American images in the media. This image, he said, is a stereotype dating back to slavery of black men as the black brute, a menacing figure always stirring up trouble.

"That image was developed then, and it has continued to evolve so that now it is so entrenched in our society that everybody is affected by it, including blacks," said McCall, who has attended several hoodie rallies. "I see all of this as challenging the stereotypes. It is a challenge to society to look at its contradictions."