[quote name='Katsu']Oh my lordy lordy lord.
I've got so many damn theories.
[spoil]
1) What if Itachi was possessed by Madara the night of the massacar, causing him to be 'tested on his compasity?'
2) Itachi never killed the clan, it was Madara casting a Genjutsu on Sasuke and the clan, making them think it's Itachi.
3) It was blackmail
4) The Uchiha clan were evil, so Itachi killed them. (bad theory)
5) Madara killed them, then Itachi took the blame (after being blackmailed into Akatsuki) and became a Spy for the J-man.
=/ I have more, but I can't think.[/spoil][/QUOTE]
I like the 5th theory