D. Dieks examines a proposal for faster-than-light communication using an EPR-type setup. He shows that such communication is not possible due to the linearity of quantum mechanical evolution laws. Although quantum theory predicts correlations between spatially separated systems, these correlations do not allow for message transmission at superluminal speeds. This is because operators for measurements at space-like separation commute, making expectation values of physical quantities independent of the decisions made by one experimenter. Herbert proposed an alternative method using a single experiment with a "multiplying device" to transmit information. However, this method is inconsistent with quantum mechanics. The paper demonstrates that the quantum mechanical evolution laws prevent such a "quantum communicator" from functioning. The paper shows that the proposed method fails because the state predicted by quantum mechanics does not match the required final state. Therefore, quantum mechanics does not allow superluminal communication. The linearity of quantum mechanical evolution laws is essential in preventing causal anomalies.D. Dieks examines a proposal for faster-than-light communication using an EPR-type setup. He shows that such communication is not possible due to the linearity of quantum mechanical evolution laws. Although quantum theory predicts correlations between spatially separated systems, these correlations do not allow for message transmission at superluminal speeds. This is because operators for measurements at space-like separation commute, making expectation values of physical quantities independent of the decisions made by one experimenter. Herbert proposed an alternative method using a single experiment with a "multiplying device" to transmit information. However, this method is inconsistent with quantum mechanics. The paper demonstrates that the quantum mechanical evolution laws prevent such a "quantum communicator" from functioning. The paper shows that the proposed method fails because the state predicted by quantum mechanics does not match the required final state. Therefore, quantum mechanics does not allow superluminal communication. The linearity of quantum mechanical evolution laws is essential in preventing causal anomalies.