When a killer begins brutally murdering popular users of large social media networks in Maryland, the BAU searches for an unsub who is taking on the persona of an Internet urban legend. Meanwhile, Morgan and Savannah struggle to find quality time for each other with their busy careers.
- Kathleen Ammermuller - Velma Bradford
- Rochelle Aytes - Savannah Hayes
- Tara Christopher - Priscilla Abel
- Dennis D'Antin - Reporter
- Keiko Elizabeth - Sara Denslyn
- Seth Ginsberg - Daniel Osbourne
- Gev Kalian - Austin Bateman
- James Austin Kerr - Connor Holt
- Rebecca Kessler - Pedestrian
- Andrew Manning - Leo Holt
- Paul McKinney - Charles Lorne
- Ian Nelson - William Pratt
- Nazanin Nour - Doctor Joyce Giles
- Chris Prascus - Alexander Chase
- Jay Renshaw - Riley Summers
- Shelley Robertson - Detective Dawn Rosenberg
- Alyssa Gabrielle Rodriguez - Kimmy
- Jason Sino - Kyle Bridge
- Ana Walczak - Tara Harris
- "Break Me" by Babe Youth
- "Famous Overnight" by The Hundred Days
- Derek Morgan: "Naïveté in grownups is often charming; but when coupled with vanity, it is indistinguishable from stupidity." — Eric Hoffer
- Derek Morgan: "There is a fellowship more quiet even than solitude, and which, rightly understood, is solitude made perfect." — Robert Louis Stevenson
- In one scene, Morgan remarks, "...[T]he internet is forever." This could be a reference to the Season Five episode of the same name, which also revolved around the Internet as one of the narcissistic unsub's attributes.
- There are references to Buffy the Vampire Slayer throughout the episode, with several characters named after characters featured in the series and the school mentioned in the episode bearing the same name as the town of Sunnydale, which is also featured in Buffy.
- YouTube personality iJustine, who is mentioned in this episode, previously guest starred in the Season Six episode Middle Man as Meredith Joy.
- What's interesting to note is that a man named David Kalac murdered his girlfriend and posted a photo of her corpse on 4chan just one week prior to this episode's airing. It's also interestingly similar to what the episode's unsub did to his victims and may have even been an inspiration.