James Franco claimed that Alien is based on underground rap artist Russell Stuart alias Dangeruss. There was much speculation that his character was based around another rap artist by the name of Riff Raff. Franco dismissed those claims when speaking to GQ in 2012, yet he posted a picture of himself online with pictures of Riff Raff on his wall and referring to himself as "film game riffraff". Also, Riff Raff released e-mails between himself and Harmony Korine in which Korine offered Riff Raff the part of Alien. Riff Raff is filing a $10 million lawsuit against Korine and spoofed Franco in One Life To Live.
Emma Roberts was originally cast but the film required her character to indulge in a three-way sex scene, causing her to drop out of the film due to unspecified "creative differences." She was replaced by Ashley Benson.
In a Howard Stern interview, James Franco described some of the movie's filming locations as "real locations where there were real gangsters around and real bad stuff going on." Franco specified that Vanessa Hudgens was very scared while shooting the scene at the pool hall, contrary to the behavior of her character, Candy.
The gun barrel blow job scene arose from improvisation on set. Harmony Korine suggested the girls emasculate Alien by sticking the gun barrels in his mouth. It was then James Franco's idea that Alien would get turned on, leading him to perform oral sex on the guns.
A sequel, Spring Breakers: The Second Coming, has been announced, with Irvine Welsh and Jonas Åkerlund taking over directing credits from Harmony Korine, writer/director of the original. Both Harmony Korine and James Franco have been vocal about their disapproval and non-involvement in the project, with Franco posting online saying, "This is not being done with Harmony Korine or my consent. The original was wholly Harmony's creation and these producers are capitalizing on that whoever is involved in the sequel is jumping on board a poison ship...Can you imagine someone making the sequel to Taxi Driver (1976) without Martin Scorsese and Robert De Niro's consents? Insanity! I'm speaking up for Harmony and his original vision and for any creative person who cares about preserving artistic integrity."
Director Harmony Korine cited Miami Vice (2006) as a primary influence on Spring Breakers: "The movie I watched most, believe it or not, was Michael Mann's "Miami Vice". The reason I love his movies, and that movie in particular, is I could feel the place. When I watch that film, I don't even pay attention to what they're saying or the storyline. I love the colors, I love the texture." 
The ATL Twins' backstory, regarding them sharing women, etc., is all true. In fact, according to an interview with Vice, the pair have not had separate girlfriends since the 6th grade and were, at the time of the interview, in a serious relationship with one woman.
Spring Breakers is to be rebooted as a digital series, fulfilling the prophecy of "spring break forever". The series will premiere on the upcoming Blackpills platform. Chris Hanley and Fernando Sulichin are still to produce while Harmony Korine isn't involved with the project.
James Franco has the name "Alien", Riff Raff the rapper who was portrayed in the film without permission released an album, "The Golden Alien" in July 2012. "Spring Breakers" was released in March 2013.
The trivia items below may give away important plot points.
At the end of the film, Brit and Candy are shown calling their parents at a convenience store prior to the massacre. In wider shots, you can see Big Archie's Orange Lambo next to them, implying that these phone calls are actually taking place after the shooting.