Who is responsible if a repeater inadvertently retransmits communications that violate FCC rules?

The control operator of the originating station is responsible if a repeater inadvertently retransmits communications that violate FCC rules. This is because the originating station is deemed responsible for the content being transmitted, as they initiate the communication that is subsequently retransmitted by the repeater.

In the context of amateur radio, the FCC places the onus on the control operator of the station that is generating the transmission to ensure that their communications comply with all regulations. If the content violates rules, regardless of whether it goes through a repeater, the originating station's control operator is ultimately accountable.

This highlights the importance of being knowledgeable about the content you are transmitting, as well as understanding the potential for that content to be amplified or retransmitted by other stations.