The phenomena where a fact based post is given negative comments or down voted because:
1. It wasn't funny
2. It contradicts funny yet wrong posts
3. The post writer isn't as well known on the forum as other
4. Readers don't like the facts the post writer presented
These happens despite the fact the post writer's answer being verifiable as correct.
The Langston Effect is apparent on UD in the definitions of zipperhead and dubstep amongst others. See also almost anything on yahoo answers.