This is a dreadful doctrine. Even if we take the list of so-called "sins" enumerated in this video on face value (which, in fact, there is no good reason for), hiding what you're doing is the worst thing you could do. It's a form of psychological isolation, which prevents you from getting help, increases the likelihood of things like suicide or aggression, and stunts any capacity for growth. If this is how Islam is telling its adherents to behave, then I pity them.