The film's shaky camera style of cinematography, dubbed "La Shakily Queasy-Cam" by Roger Ebert, caused some viewers (particularly in darkened movie theaters) to experience motion sickness, including nausea and a temporary loss of balance. Audience members prone to migraines have cited the film as a trigger. Some theaters showing the film, such as AMC Theatres, provided poster and verbal warnings, informing viewers about the filming style of "Cloverfield", while other theatres like Pacific Theatres just verbally warned customers in detail at the box office about experiencing motion sickness upon viewing the film and what to do if they had to step out and vomit.