My answer to you Wedge is whoever outed themselves impulsively. Let's begin with Faris. She only confessed when Rikku said that she had a gun, which goes against her tracker ways. Not to mention said tracker role-claim has been going on for most of the game and no one suspected a thing.

As for me, for half the game I've been sadly absent due to other stuff but from Day Five onwards I've made time for Mafia. Have I been acting against the town? Of course, but then Faris has been doing it in secret and more cleverly. She's made it this long unexposed; hell even Rikku expressed surprise at her actual role. Is Faris the better player? Almost certainly. She knows (as has been proven countless times) how to spin the town for her own end.

By lynching Faris, you are effectively lynching the better player. While I think the town is awful, even I know lynching Faris is the better option for town.

"But Penelo!" I hear you cry. "You said that Faris is a betrayer for helping town now, aren't you doing the same thing?"

Well, yes, I am effectively giving town some advise, but it is all in the effort of self-preservation. In terms of the game, I am all alone. Faris openly says she wants to help town now, which is just plain awful. While I'm helping town (by killing Faris) it is only in the interest of self-preservation.

There. You decide.