Wasn’t the smiley face badge a product of the late 60’s, early 70’s, around the time of keep on truckin’ and Robert Crumb?
Isn’t that what ‘prior art’ is supposed to mean? Certainly Watchmen predates that copyright attempt.
And the watchman badge is not just the smiley face, it’s the bloodstain on various points on it (I believe it was as a clock hand on the original twelve Watchmen comics, moving towards midnight)