The ideational equivalent of genocide. A meme is an idea. Memes are to cultural evolution what genes are to biological evolution, any idea that spreads or doesn't dependent upon culture's evolutionary process. Memocide therefore is any sort of absolute-faith-based fundamentalism, a holy war to eradicate from culture all traces of an idea considered evil by someone whose confidence level in a countervailing idea reaches 100%.
Did my folks like my punk music? Are you kidding? Their response was memocide. If they could, they would have eradicated punk not just from our house but from the universe!