I was furious on Bloodiron today as during the invasion, as Ember Isle is free pvp even if you don't want to, the defiants built a huge raiding force and wiped out the guardians who had done most of the work. Pvp being always on there also goes against the plot as it states "Guardians and Defiants will join hands to destroy the dragons." It didn't happen there! It's more like the guardians are teaming up with the dragons just to be able to make it out without being pvp mobbed!
SOLUTION: Stop pvp during invasions in Ember Isle