Police say he made threats on Facebook about "the biggest shootout killing" and warned people not to go to the April 12 event downtown.
Malone's public profile shows he posted a photo of a plastic tub full of guns Tuesday. Multiple people tipped authorities off to the posts, Metro Police said.
Louisville Mayor Greg Fischer has said police will increase their monitoring of social media sites after a group of teenagers used Facebook to organize into a violent mob that terrorized downtown on March 22.
But the police department's biggest crime-fighting tool is the public when it comes to social media, said Jeff Rushton, director of digital media at the University of Louisville.
"In the case of someone making a threat on other people's lives, call the police," Rushton said. "Don't kid about it. If you can tell they're being serious about it, do something about it."
Rushton, who monitors who's talking about the university through online search sites such as Hoot Suite and Bottlenose, said police have more-sophisticated types of search technology to aid them.
"They can predict based on posts what they're going to do, where they're going to be, what times they do certain things," he said. "The more people post, the more we know and the more we can predict where they're going to be."
Malone's next court appearance is scheduled for April 14.