A Prayer for a Stroke

Found myself praying for someone to have a stroke today (take it easy, not a fatal one, just enough to incapacitate this person so that she couldn't continue her hateful ways). Is that wrong? And if so, why does it feel so right (Luther Ingram?)? This was my prayer: "Dear Jesus, if you do me this solid and fell this wretch with a mild stroke, I will be your number one fan and lifelong supporter. Thank you, sir" (a nice touch I thought considering He probably doesn't get a lot of those). I've got my fingers crossed! Is that wrong (again with the Luther Ingram allusion!)