When a Progressive, Liberal or Democrat posts something incredibly stupid on a "left-wing" message board (such as DemocraticUnderground.com) that the freepers can use as part of a straw man argument to discredit their critics.
Publishing a ridiculous anti-Bush theory that can easily held up for ridicule to discredit the real anti-Bush theories.
Publishing a ridiculous conspiracy theory that casts the legitimate conspiracy theories in a bad light.
"Will you please stop saying that the oil companies caused the Tsunami. That's just plain stupid, and all you are doing is feeding the freepers."