It is illegal to watch certain types of content on the internet, primarily due to copyright laws and content restrictions. Specifically, watching pirated or copyrighted material without permission, such as movies, TV shows, or music, is illegal. Additionally, content like child pornography is illegal to view, produce, or distribute. To avoid engaging in illegal activities, users should rely on legitimate streaming services, pay for content when necessary, and be cautious about the content they access and share online.