1. The curse that appears in Naruto that states that any time an Akatsuki MEMBER removes his/her cloak in BATTLE or it gets removed in some way or fashion, that member WILL DIE. It does not matter if it is burned off or simply thrown away that character's death is imminent.
2. A theory that has not been dis-proven yet as every member of Akatsuki that has removed their cloak in battle has died from this curse. One could also say that instead of it being a curse that the cloak simply gives a member a mystical protection which protects them from death as they are so badass with it on and cant possibly be killed. Essentially, having the cloak on makes them invincible. It is only when taking it off that they are they vulnerable.
3. The Akatsuki is also an underworld modeling agency where the members in it are all strippers required to wear nail polish, jewelry, and take off their cloaks to reveal their chests to the fan girls. Once they do the fan girls with their malice eat them. I mean come on, most of them don't even wear a shirt under their cloak.
4. Once an Akatsuki member takes their cloak off and reveals their final move, that member will die horribly.
.Orichimaru was no longer an Akatsuki member so it didnt apply.
.Sasuke and Tobi/Madara have plot shields which protect them from death until they satisfy the plot.
. None of the Pains were technically alive to begin with
Still no member has died with their cloak on, so its power is evident
Guy 1: "WTF! Kisame just got killed off in like two chapters. Biggest epic fail in naruto yet. He's been in the series from like the beggining. He deserved a better battle."
Guy 2: "Its yet another example of the fucking cloak curse man. Kisame shouldn't have taken off his cloak. Then he would have lived"
Guy 1: "Wow Deidara is fighting off team guy with no arms and holding his own."
Guy 2: "Its cause he still has his cloak on"
Guy1: "NO Itachi!!! Whatever you do dont take off your cloak. You are so much cooler than that fag Sasuke!"
Guy 1: "Its cheap how Kakuzu was taking on Kakashi, Choji, Ino and was about to rip their hearts out. Then he was still going to take on naruto, yamato, sai, sakura and the rest all at once. But then they all teamed up on him cause they're wimps and naruto got lucky."
Guy2: "He would have won if he still had his cloak on"