Fear of a Black Planet

Public Enemy
Fight the Power
Chuck D's heros would include people like Malcolm X and Marcus Garvey which do not appear on stamps.
Fight the Power
This lyric explains that the heroes of the rapper in this case are unconventional or not considered worthy enough of commemoration on a US Postal Service stamp.
Fight the Power
Role models of Chuck D are outside of the accepted normal mainstream culture and therefore would not be depicted on a United States Stamp, also a defaming statment regarding Elvis and John Wayne both unabashed racists.
911 is a Joke
In ghettos it usually takes an absurd amount of time for the police to arrive on scene after a crime is reported. Public Enemy are implying that a taxi cab will arrive more promtly than a police officer