Anthony D. Romero current Executive Director of the ACLU.
When I was a teenager one of my favortite programs was the Firing Line Debates hosted by William F. Buckley. The only time I ever disagreed with him was on the question of whether the ACLU did more harm than good. Now, I know that the ACLU is a far from perfect organization. But I firmly believe they do far more good (see here) than harm and I offer the above quote as a part of my justification for that position.