Its in the first paragraph. So no, a warning wouldn't suffice. Jfc. Read
And yes, I know it's open source and someone can remove the block, but Mozilla and other companies can still be forced to put it there and leave it up to users to figure out. They probably can give vague instructions, but they probably have to avoid too much detail to stay out of legal trouble. What level of understanding do you have of the world outside your parents' house?