14w07a execute

When using the execute command, i would like to hide the gray text in chat that shows what the entity did. For example, i am using snowballs. It says "emphasis[Snowball: Teleported Snowball to 215.5 54.0 123.5]".
I tried using gamerule commandBlocOutput false and even gamerule logAdminCommands false.
It still shows the text. Is this a bug or is this intended? Any way, please add a feature to hide it.