Complex sentence: In late October of 2012 the GNAA hacked several Wikipedia articles related to the Halo video game franchise causing a page revealing several spoilers from the up and coming Halo 4 to be shown.
Split into simpler sentences: In late October of 2012 the GNAA hacked several Wikipedia articles related to the Halo video game franchise. It caused a page revealing several spoilers from the up and coming Halo 4 to be shown.