Those of you who may not have understood why yesterday's news about FUNimation's release of One Piece episode #403 getting distributed worldwide by an unknown user who compromised FUNi's servers was such a big deal, perhaps this will help lay the issue clear.
FUNimation has pulled Fullmetal Alchemist: Brotherhood from their video network. No statements have been released as to why yet (it's Sunday after all) but there are many possible explanations. The most benign is that they took them down while re-evaluating their servers' security. On the other hand, they've left Phantom up-- but Phantom isn't the big-name release FMA is. FMA is still available on Hulu, and the first four episodes are still on YouTube.
Still, it seems more likely (and this is all speculation on my part, of course) that the Japanese companies through which FUNimation licensed FMA for online release have requested that the episodes be pulled. And hopefully if that's the case, it's merely a temporary measure to assure security of the episodes.
Let me reiterate that this is speculation and that until we hear word from FUNimation on the matter, we do not actually know why FMA has been pulled-- but I expect that we'll hear pretty soon.