They was planning a group to take over the leaf village...This is explained when Tobi talks to Sasuke about the truth of Itachi
how could you believe that masked dude, when he lied about being the actual madara
and tsunade said that the name is power itself. meaning that anyone with the right attribute, Being an uchiha is most likely seeing as everyone believed that all but two uchiha lived through the massacre, the one who massacred and the one left to tell the tale, and so using that confusion, as well as making sure to tell sasuke about the truth, after itatchi died so that sasuke would not be able to be told the truth about what happened by itatchi making it so easy to lie to sasuke who was in quite a state of shock.
also sasuke asked itatchi who helped him? because even for itatchi, he wouldn't have been able to take the whole clan down by himslef, and itatchi replied saying that madara uchiha helped him, which kinda kicks the idea that the elders told itatchi to do it out the window, i mean, why would the elders ask itatchi to kill his clan with the help of madara, cause they would want any info leaking out.
now also, danzo had shisui uchihas eye, with the ultimate genjutsu, and cooperated with madara because it allowed him to obtain the other ten sharingan for inzangi, and so he put the third, and the other two elders under his conrtol and used them to make itatchi do it, because why the hell would itatchi do something kill his clan if danzo told him, no he would need to be told by the highest ranking ninja in any village, the kage.
any thoughts?