The example that caused me to stumble upon this is the Laughing Man from Ghost in the Shell Stand Alone Complex. While this logo

Can be perceived as many things it has no true signifier attached. Its name was (within the story) given after its use. Its text is a quote from Salinger's "The Catcher in the Rye." (The name Laughing Man is a reference to Salinger short story) and could contain multiple forms of meaning. Esspecially indicative is that the text ends where it does and doesn't include the rest of the line "or should i?"
Maybe my brain is just tired but the concept of knowledge without origin and a symbol without a symbolized object just seems plausible with how hyperactive our society is becoming.