Seung Hui Cho: Wrote in his manifesto about Eric and Dylan as "martyrs" and made a project about Columbine during his high-school time.
Pekka-Eric Auvinen: Was very active in the Columbine-community at Youtube. His Manifesto appears to have several allusions to Erics diary.
Matti Juhani Saari: Took a pilgrimage to Jokela High School, where Pekka-Eric commited his rampage. He also bought his weapon from the same company like Auvinen. And like Auvinen, he set fire at the school, during the shooting.
Kipland Kinkel: Told his friends, that he thought the Westside Middle School Shooting was "cool".
Andrew Wurst: Told also his friends, that he thought the Westside Middle School Shooting was "cool".
Robert Steinhäuser: Took a deep research about Columbine at his fathers PC. He also told his friends, that he thought the Columbine Shooting was "good, not only the shooting itself, but also the way it was made"
Tim Kretschmer: Took a deep research about Columbine, the Erfurt School Shooting (Robert Steinhäuser) and the 9/11 Terrorists at his PC.
Steven Kazmierczak: Took a deep research about Columbine, Virginia Tech, Ted Bundy and several other mass shooters/serial killers.
Wellington Oliveira: Called Seung Hui Cho a brother in one of his Videos and also referred to an unnamed brazilian school shooter.
Adam Lanza: Collected information about "virtually every mass murder" at his PC, but appears to had a special interest in Anders Behring Breivik and the 2006 Amish School Shooting.
Martin Peyerl: Told someone, that it was "completely crazy what these guys (Eric and Dylan) have done" and that he believed Harris' and Klebold's actions to be "something we should do".