The North American anime distributor Funimation has issued a new statement in regards to the leak of One Piece episode 403:

As anime fans know, FUNimation Entertainment and Toei Animation had planned for the first ever online simulcast of the series ‘One Piece’ tonight at 9:00 pm CDT., just one hour after its premiere on Japan's Fuji Television. Unfortunately, in the last 24 hours we have determined that the FUNimation servers were compromised, even though we employ strict security standards. An unknown individual accessed and posted episode 403 online and as a direct result of this illegal act, all U.S. and Canadian fans will be deprived of access to this great anime series for the immediate future. We will make every effort to locate and prosecute the perpetrator(s) to the fullest extent of the law and will provide updates regarding this most serious matter.
Funimation has also replaced the original statement on its website — which less specifically stated that One Piece was not available due to technical issues — with the above statement.
At this time there is no further information as to if, or when, the One Piece simulcast will start.

Update: One Piece has also been removed from Hulu (Google Cache). Hulu was set to offer subtitled One Piece episodes seven days after the Japanese broadcast (Funimation's simulcast was to be delayed by only 1 hour). Hulu had acquired One Piece from Toei, not Funimation.

Update 2: One Piece has also been removed from Joost (cached). Although Joost has not removed it's One Piece page, the episodes have been removed and replaced with the message "Sorry, this channel is not available in your country."