Niger, the country.

[Y-Less]

Niger is a literal country in Africa. A whole country. And yet way too many systems block its name because it is close to another word that some people don't like. Imagine being unable to talk about your own home country online! This should IMHO be added to the Scunthorpe Problem section. If not my favourite sentence:

Dams and dykes retard water in Niger.

[Ferroin]

Seconded. This is a rather notorious false positive for profanity filters in a number of gaming communities (off the top of my head, both Minecraft and Warframe flag Niger, as well as Nigeria).