In 25 hands I was dealt KK/QQ/AA (x2) and lost all of them to a maniac.
Hand 1 - I have A[d] A[h] and x5 pfr. Flop A[c] Q[d] 5[s]. Another guy has 5[h] 5[d] so I finally get to set over set someone. We're all in on the flop and maniac calls to draw to his gutshot. He hits it.
Hand 2- I have K[d] K[h]--I raise to x10BB and maniac calls with a full stack with 8[d] 2[d]. Flop J[d] T[h] 3[h]. I btp, he pushes and I call. Turn and River diamonds.
Hand 3--I have Q[d] Q[s] and x5pfr. Maniac calls (of course) and so does a rock (uh oh). Flop T[h] T[d] 9[d]. I btp, rock pushes, maniac calls, and I fold. Rock had Q[h] Q[c] and maniac had 9[h] 9[s].
Hand 4--I have A[s] A[c] again. The gods want me to bust this guy. I'm getting AA again in less than 25 hands. No wait, they don't. I raise x5BB and maniac calls Q[h] T[s]. Flop J[d] 6[h] 7[h]. I bet 1/2 my stack on the flop and he calls. Turn 8[d] and I push he calls. River 9[s]
I should just avoid maniacs. I lose more than 50% of my losses to them.