All of the Final Fantasy worlds would be much more peaceful without these crystal things.

The Final Fantasy XI "Crystal War Revisited" event has begun! You can read an amusing article with chatting moogles that focuses on it at the official FFXI website.

Which nation do you think was most influential in the outcome of the Crystal War?
San d'Oria and its noble knighthood? Bastok and its formidable artillery? Windurst with its unparalleled magic?
This controversy can only be resolved by you!
Capture crystal fragments from beastman-held positions to attain victory and glory for your nation!

Read it here.