Nether Brick Fence

Nether Brick Fences were added to the Nether as a part of Nether fortresses in 1.9pre1. Currently, Nether Brick fences cannot be set on fire, unlike wooden fences.

Natural Occurrence
Nether Brick Fences are naturally found in Nether fortresses where they form window bars and gate-like structures.

Usage
Nether Brick Fences do not burn and have the same blast resistance as most stone blocks, which makes them useful in creating Ghast-proof structures. In areas frequently bombarded by Ghasts, Nether Brick Fences are useful for shielding light sources. They connect to most blocks, including wooden Fence Gates, in the same manner as wooden fences. However, they do not connect to wooden fences. By combining sections of the two types of fences, it is possible to make barriers that players can navigate through, but most mobs will get stuck in. However, one should bear in mind, that in case there is a group of monsters trying to get to the player (e.g. a mob of zombies), the ones in the back can easily push the ones in the front through this kind of a fence, because collision allows it.

Trivia

 * Nether Brick Fences require 6 Nether Brick for 6 pieces, but 6 Sticks would only craft into 2 Fences.
 * Once a Nether Fortress has been found, Nether Brick Fences are an easier option than Wood Fences, since there are so many Nether Bricks to make into Nether Fences.