Sorry, but I know that I have. Anytime I hear that from the rubbery lips of some clueless skeptic, repeated without even understanding its underlying meaning, Mr. Hand forms into Mr. Fist, mentally speaking. American astronomer, astrophysicist and author Carl Sagan popularized the statement: " Extraordinary claims require extraordinary evidence," and we find it being employed as a brute force tool by a great many of our modern-day Skeptics and Scholars. However, this represents an unscientific statement on Sagan's part, in that he does not bother to define his principal variable; that is, the word "extraordinary". If a scientist is not completely open to examining evidence that has never been previously presented or acknowledged, then he will, quite naturally, become completely surprised by that data when it comes forward and stares him in the face. This will lead to his labeling it as "extraordinary", and that represents his own personal opinion. Every theory requires the best evidence, both for and against it, that is available. All claims, whether extraordinary or not, require this same degree of dedication to evidence. Personal opinions should not represent the major portion of that gathered "evidence"; they belong instead in the section called "conclusions" in a report. What I find extraordinary is quantum mechanics, and yet it is a well-accepted, if poorly comprehended, part of modern physics. Whenever any part of it seems to not quite "work", they come up with something like a "black hole" as a weak type of patch-work explanation for something that really should be telling them that their theory is busted, and they need to try something else. . The presence of UFOs and their extraterrestrial occupants should no longer be considered to be either out of the ordinary (extraordinary) or unanticipated. And that's my rant for the day.