I've been "burned" by exactly what pg just said, on Reddit too. And I agree, because with the labor laws, the employer has more to lose than the employee if they aired certain things. For our non-US people, in California, there are laws that specify that ex-employers cannot say bad things about an employee (a bad one or not), to the employee's next prospective employer.
As the employee, you get away with some things that "structurally" (as pg said) from the legal perspective that employers cannot.
Another perspective: in some states, such as Pennsylvania, employment by law is "at will" and you can be fired/sacked/relieved "without cause."
So you might lose your job. You'll get a reference but nothing that your future employer is really going to base a hiring decision on.
I'm not convinced that the old employer loses any money by replacing and retraining employees once you subtract raises that would have been earned and benefits, so I tend to think there's still a tremendous amount of power on the side of the company rather than the employee.
As the employee, you get away with some things that "structurally" (as pg said) from the legal perspective that employers cannot.