First they were called chain emails, and they were sent by people like your weird aunt who always wore a Big Dog t-shirt.
An online version of physical chain letters, chain emails propagated hoaxes and urban legends by convincing people they would either receive a monetary reward for forwarding the emails, or that they would fall on bad luck if they didn't. As the web grew, chunks of copy-and-pasted text proliferated outside of emails, on message boards and Usenet groups and social networks, eventually becoming an integral part of the Internet's history. Now, one viral urban legend kept alive by copy and pasting has allegedly driven two 12-year-olds in Wisconsin to try to kill their friend.
Chain emails in the 1990's resonated with readers the same way that modern "clickbait" headlines do now: Appeal to a reader's emotional side, and they're far more likely to share whatever it is you're peddling. Tell them something terrible will happen to them if they delete it, or that sharing a feel-good story about a blind dog will make them a better person, and suddenly you have a viral sensation. Chain emails were one of the first vehicles for web virality. And aside from vicious spammers and people who tried to convince you to hand over your bank account information, they were (and are) mostly harmless.
Around 2006, viral copy-and-pasted text was coined "Copypasta" by the online community 4chan, and began splintering into different genres. Copypasta's most popular genre is Creepypasta, bits of copy-and-pasted text that convey scary stories and unsettling urban legends. Creepypasta writers take popular urban legends—remember the legend of Bloody Mary?—or create entirely new subjects and fashion online stories with the intent to totally freak out the reader. They're basically short, shareable user-generated ghost stories that can focus on anything from the especially gruesome, like murder and suicide, to the creepy and otherworldly, like aliens and zombies. The most popular hangout for writers of this genre is the Creepypasta Wiki, where they can trade stories and connect with each other.
Creepypasta hit peak popularity with a 2010 New York Times story, but it still lives on. Popular Creepypastas include Ted the Caver, stories about a man spelunking a mystery cave, and Lavender Town Syndrome, a series about a fictional town that tried to cover up mass child suicides. Slender Man, who is arguably the most well-known Creepypasta character, is the reason the two Wisconsin 12-year-olds allegedly attempted to fatally stab their friend: in order to pay tribute to him.
Though Slender Man originated on online forum Something Awful, the majority of tales about him live on the Creepypasta Wiki, where the two girls reportedly discovered him. There are so many that the Wiki no longer accepts new stories about him. And now that Creepypasta has been thrust into the spotlight for horrifying reasons, the owners of Creepypasta.com have released a statement addressing the attempted murder.
In the statement, admin "derpbutt" (yep, that's the name he uses) says he tried to nudge Slender Man out of the community, but not because he thought it was dangerous:
I’ve been trying to encourage writers here to break out from the serial killers and Slenderman cliches that tend to overrun the Creepypasta fandom, though my motivation was less that I believed Slenderman was harmful (the Jeff the Killer fangirls and spin-offs, I did find somewhat troubling – I’ve mentioned before that I feel romanticizing serial killers is not really something I feel comfortable with promoting via publishing all the Jeff love stories and self-inserts that people tried to submit; the only Jeff spin-off I did let through was one that I felt had a decidedly non-romantic view) but more because I view this website as a place for people to become better writers and readers
A Creepypasta Wiki administrator who goes by the username Sloshedtrain also chimed in with a blog post called "Fiction, Reality, and You."
"This wiki does not endorse or advocate for killing, worship, and otherwise replication of rituals of fictional works," Sloshedtrain wrote. "There is a line of between fiction and reality, and it is up to you to realize where the line is. We are a literature site, not a satanic cult."