From the descriptions of the Ghast on the wiki, they only fire their fire charges when a player is within 16 blocks of them. I was in the nether, oped and in gamemode 1 and ghasts would spawn at random, as they should, but would start firing in random directions. One structure in the nether was built of glass and happened to be the target of one particular ghast. Is this normal behavior, should they be firing when there isn't a player, they can target, nearby? It's causing quite a bit of damage to the surrounding terrain, as well. IT makes about as much sense as a skeleton firing arrows at random with no target.