That was explained earlier in the program:

A state and government “of, by and for” the workers must replace the capitalist state. The foundation of any state power is repressive force—the military, police, prisons, courts and so on. The standing army and police must be disbanded and replaced by the armed people, organized in workers’ defense councils. A critical task of the new socialist order will be defending itself from the displaced capitalist class that would like to return to the days of exploitation. A workers’ government would create an entirely different type of court system, with its basic institutions determined by the democratic organs of workers’ power. Judges would not be required to be lawyers. All public officials, without exception, would be elected and subject to recall at any time by those who elected them.

It’s certainly not self-justice. Mob-rule is just a term liberals use to justify anti-democratic mechanisms to protect their own power.