The Halifax Mass Shooting Plot refers to a thwarted 2015 plan by two individuals, inspired by the Columbine high school massacre, to open fire at a shopping mall on Valentine's Day. The plot became a subject of internet fascination due to the perpetrators' deep involvement in 'Columbiner' Tumblr communities and the strange digital footprint they left behind before their arrest. Memes surrounding this event typically focus on the intersection of online radicalization, true crime documentation, and the swift intervention by law enforcement that prevented the tragedy. It serves as a dark reminder of the mid-2010s internet subcultures and is frequently discussed within true crime and internet history communities to highlight the real-world consequences of online obsession.