On a similar note, i often get "you are on a war path" even though i've never started a war and have virtually (or literally) no military power. I most often see this message from malevolent races.
Perhaps this is triggered by defeating pirates? Pirate-squashing should increase your cred, if anything.
"We are on a war frenzy" is not the AI knocking you for your actions, that is the AI declaring to the world that they have gone "UG WANT WAR, UG WANT WAR NOW!" They are on the warpath, not you.
I think the "you know what you did" mod is what happens if another faction has you designated as their HatedFaction.
