Have we had enough of exhortations to be silent?

"We've had enough of exhortations to be silent! Cry out with a hundred thousand tongues. I see that the world is rotten because of silence."


Saint Catherine of Siena

I am intrigued by this quote. I have noticed it being used by many in their blogs, but I have not found a source for the quote. Does anyone have the story behind St. Catherine's reason for saying this? I have spent some time researching this quote and the closest I can come to it is the following: "Cry out as if you have a million voices;" Catherine tells us, for "it is silence which kills the world" (Letter 16 to a great prelate). It seems her outburst was directed at the cowardly silence of certain ministers of the Gospel who, in her opinion, ought to have been crying out loud and clear on behalf of truth and justice.