One rather large-scale example, discussed in this community since the beginning of time: deathism and the general public's attitude (or lack thereof) to cryonics.
"You know, given human nature, if people got hit on the head by a baseball bat every week, pretty soon they would invent reasons why getting hit on the head with a baseball bat was a good thing." - Eliezer
Good example.
Here's the new thread for posting quotes, with the usual rules: