"The three degrees of falsehood are lies, damned lies, and statistics." Attributed to Benjamin Disraeli, Lord Beaconsfield and a famous Prime Minister of England (probably incorrectly, see http://www.york.ac.uk/depts/maths/histstat/lies.htm).
Carroll D. Wright, a prominent American statistician, said in his address on June 25, 1889 to the Convention of Commissioners of Bureaus of Labor Statistics:
The old saying is that ~figures will not lie,~ but a new saying is ~liars will figure.~ It is our duty, as practical statisticians, to prevent the liar from figuring; in other words, to prevent him from perverting the truth, in the interest of some theory he wishes to establish. We can only do this by being absolutely fair ourselves.