I honestly believe that "sending spies" is not a act to steal intel. But to achieve other goals. One of which could be just for the personal amusement of said spy and their associates. Another could be to cause drama, possibly leading to subterfuge or sabotage.
Or, at least that's the only thing I think someone could possibly get from such actions. On the other hand, its only natural to want to provide for your guild and not everyone else's. Say you came up with a good strategy for something related to the game you play. You may only want to share that helpful information with your guild only. Nothing wrong with that.