Aggressive youth is a term used to describe young people who display aggressive behavior, often in the form of violence or vandalism. YOB is an acronym for 'youth of bad behavior' and is often used to refer to these individuals. Aggressive youth are typically characterized by their lack of respect for authority, disregard for social norms, and tendency to engage in risky activities. They are often seen as a threat to public safety and can be difficult to manage.