“Deadcon” (** out of four) was a trifling horror thriller about a group of social media stars (Lauren Elizabeth and Claudia Sulewski) who soon find that they are endangered and being stalked by someone unknown through their various social media accounts. Thinly done horror satire about the world of social media and youth culture comes up short on both scares and laughs. Even at only 78 minutes, this starts running on empty pretty quickly.