Tyler is a nerdy photographer who deals with intense bullying at school. He stalks Hannah by hanging around outside of her window and taking photos of her, and when she refuses to go on a date with him, he distributes photos of her kissing Courtney in retaliation. When Clay finds out what Tyler did to land on the tapes, he sends a naked photo of Tyler to the entire school, because he feels it will in someway offer Hannah some small bit of justice.
Instead, his actions only make Tyler's already difficult high school experience harder. In the finale, he's seen with a huge cache of guns, and it's implied that he could be contemplating a school shooting.