There are certain things that the YouTubers must not do. YouTubers must stick to YouTube community guidelines. They should not post:
1). Hate speech or harassment
2). Copyrighted content without authorization
3). Harmful or dangerous activities
4). Explicit adult content
5). Scams or spam the viewers.
If any of these are breached, it might lead to strikes, demonetization, or even banning from YouTube.