Probably not, but for those who have, there are six websites in the United States currently selling "murderabilia," or murder memorabilia, from almost any killer imaginable.
The starting bid on Manson's hair is $2,500, and the starting bid for a Gacy of an owl is $1,300 on MurderAuction.com.
In addition to top-sellers like Manson and Gacy, buyers can purchase items from infamous killers like Ted Bundy, Jeffrey Dahmer and Richard Ramirez.
The objects range from personal items such as letters, artwork, and clothing to manufactured items such as action figures, trading cards and comic books.
But the controversial business of selling murder memorabilia does not sit well with many people, including Andy Kahan, a victim advocate for the city of Houston who has been the leader of efforts to ban these sales for many years.
Kahan calls the sale of murderabilia a "wacky, insidious industry."
"It's one of the most egregious things I've seen after being involved in the criminal justice system for 25 years," Kahan said. "I was just stunned and mortified that individuals can commit these types of offenses and go on to further claim infamy and immortality."
Dealing in Charles Manson's Hair or John Wayne Gacy's Art
When Kahan discovered murder memorabilia being sold on EBay in 1999, he made it his mission to stop the sales. He eventually convinced EBay to outlaw the selling of the products, but the vendors had already tapped into a niche market and discovered there was demand for the objects, so a handful built their own websites.
One of these was Eric Gein, 42, who owns and operates Serial Killers Ink, one of the sites that sells murderabilia, from his home in Jacksonville, Fla.
"I started writing guys in the mid-90s," Gein said. "I wanted to get inside their minds and see what made them tick, see what they did and why they did it."
Gein said he discovered that buyers have a fascination with "going to the source" and "holding something that an infamous monster has created," which led to his business.
The vendor befriends the prisoners by writing them letters and starting a relationship.
"You can't write Manson and say, 'Send me some artwork.' It doesn't work like that," Gein said. "The relationship we have with these infamous serial killers, it takes time, it takes trust. You have to build a friendship, build a relationship just like you would with anyone else."
He said that once they have developed a relationship, he is forthcoming about the fact that he is looking to sell items from them. Gein said that many of the criminals thrive on attention and see the products as a way to garner attention.
Gein's customer base is diverse. Buyers include "collectors of the macabre," university professors who use the items for teaching, college students looking for dorm decorations and military men and women.
Some of the most popular items on his site right now are a signed angel postcard from Charles Manson, on sale for $225, and a handwritten letter and envelope from Ted Kaczynski, better known as "the unabomber," for $250.
While Gein will not say how much he makes from these sales, he said he makes "a comfortable living." He and his girlfriend keep 100 percent of the profits and say none of the money goes to the inmates.
When asked if he feels guilty for what some would see as profiting off of heinous crimes, Gein insists he does not.
"I don't feel badly at all," Gein said. "I am desensitized to the crimes. When I'm in contact with these guys, I'm not thinking, 'Wow. This guy destroyed 30 families.' I'm thinking, 'This guy can make me money.' It may sound brass and cold but that's the reality for me."
Murderabilia Dealers Say They Make a Killing in Collectors' Market
Gein said he is aware that some family members of victims of these killers are hurt and angered about what he does for a living.
"While they do have a right to speak out against me, they don't have a right to try to shut me down," Gein said. "I run a legal business and I'm catering to a market that is in demand. I'm not a monster. I can't say I understand their pain because I'm not in their position."
One woman who has spoken out is Dee Sumpter of Charlotte, N.C., whose daughter Shauna was killed by serial strangler Henry Wallace.
"The way he killed Shauna was a personal killing," Sumpter told ABC News' Charlotte affiliate WSOC-TV. "It was with his hands, and the unmitigated gall of him to sell a photo or an artist rendering of such—I don't have words."
A sketch of Wallace's hands is on sale online for $100.
"Have a conscience. Have a heart. Have a mind," Sumpter pleaded. "Legislatively, I know there has to be something that can be done to stop this."
Unfortunately, as Kahan has found, passing legislation is difficult because, technically, these vendors are not doing anything illegal.
"Son of Sam" laws keep criminals in many states from profiting from their crimes through books, movies or television shows, but in these murderabilia businesses, it is a third party selling the items, which is legal. And if the vendors choose to send money or gifts to the imprisoned criminals, that is their choice.
"Unfortunately, they're correct. It's legal," Kahan said. "I'm a firm believer in free enterprise and capitalism, but you should not be able to rob, rape and murder and then turn around and make a buck from it. It's that simplistic."
Kahan has twice attempted to file a federal law that would prohibit the selling of these goods but has not been able to get a hearing.
Tod Bohannon, who runs Murder Auction, defends not only his business, but the criminals as well.
"A lot of people think these inmates are sitting around eating donuts all day, drinking Coca-Cola and laughing about their crimes," Bohannon said. "A lot of these guys are remorseful and they're doing the time for what they've done. Why should we continue to humiliate them?"
Bohannon does concede that not all of the criminals are remorseful, with some writing letters proudly spinning stories of their crimes, he said.
Bohannon said that while he does not pay the inmates for any of the items they send, he does not deny sending them money. He said there is one inmate that he sends $20 to every week.
Kahan takes no comfort in these explanations and continues to fight against the sales. Eight states have notoriety for profit laws that prevent criminals from profiting from the sale of personalized items, but these laws are often difficult to enforce. Since buyers are often from different states, or even countries, the transactions turn into matters of interstate commerce.
Still, Kahan says he continues to fight because he so passionately believes these businesses should be illegal.
"From a victim's perspective, nothing is more nauseating and disgusting than finding out that the person who murdered your loved one is hocking items to make a buck," Kahan said. "It's like being gutted all over again by the criminal justice system."