Guild Wars 2 introduced the first wing of its new raids to players yesterday. To make these new raids as good as they could possibly be, ArenaNet recruited high-end guilds full of raiders dedicated to achievements like world first clears. The idea was that these guilds would take part in the testing but would not then immediately brag about world first kills after months of practice on this content no one else had played.
It appears that the guild Death and Taxes did not get that particular memo. The guild has now been removed from further raid testing, and a valuable lesson has been learned about raid drama. Further raid testing is ongoing; you can read the full statement from ArenaNet regarding the removal just below.