The spiral is a symbol of Konoha. It can be seen on the battle vests worn by chuunin and jonin rank shinobi. Naruto’s costumes in both part I and part II incorporated it into their design. And the Rasengan is basically a spiraling sphere of chakra. What’s all this have to do with Tobi/Uchiha Madara? His mask, it’s a spiral.

Now, most Akatsuki members wear their original village’s head protector but scratch a line through the symbol to show the have broken their bonds and have become …

Something I grabbed off from the episode 22-23 hour-long special and pasted together. Kakashi got in the way of the last frame though, what an attention hog.