Public service announcement

Public Service Announcement - a short commercial-type message, usually done by a celebrity, to explain or emphasize a point. The network or station transmitting the PSA does not received payment for the transmission, as opposed to a commercial or info-mercial.

During the 4th season of 24, Keifer Sutherland appeared in a PSA, explaining that the day's events are ficticious and in no way suggestive of any real terrorist cells being formed by immigrant or naturalized Americans. This was in response to several groups public messages that Americans of Arab descent or appearance were being targeted for harrassment due to the depictions of characters on 24.