OMG, there is someone else who is experiencing this? I swear, I have used up all patience and trying to be kind when dealing with this.
I created my primary email account cupcake@mac.com a very long time ago. Of course, it morphed into cupcake@me.com and most recently into cupcake@icloud.com. This behavior occurs with all three variations, but most often with the "@me.com" address. In trying to understand the timeline, I figured it started occurring about the time of the iOS release 5.
I get approximately 10 account creation emails a week. Mine range from harmless to education to medical to ****. At one time I was getting as many as a hundred a week! I also send very politely worded emails to the companies explaining that someone tried to sign up with one of the variations of my emails and ask them to delete any or all accounts associated with them. Unless of course, they are ones that I want to keep.
The problem with telling companies to delete the accounts is that it is now sitting out there for someone to setup the account AGAIN. I have started simply requesting a new password or password reset, change the public facing data and leave it be. This will only work with accounts that require email validation, though. I have stumbled upon accounts while trying to create my own! Again, I simply change the public facing info and password and email. It then becomes mine. I've had a couple of accounts - a Disney site - that won't reset the password or delete the accounts because I can only validate the email address and none of the other account info! Sigh.
I have worked with Apple many times, sometimes for many hours trying to resolve this issue. Apple tends to be myopic and generally sticks with "someone just mistyped the email"... but it happens much too frequently for this to be true. I know it is a popular and coveted email address and perhaps people think they can force the company to recognize it as their own. I've also had requests for the Apple accounts to be reset.
Recently had an interesting chat on Apple's Messages with an 8 year old who swears that it is her friend's iChat account. She admonished me to be nicer if I was sharing it with her friend. I couldn't make her understand that her friend was incorrect in believing it was hers.
I see that you've written your message way back in February and I see no other follow ups. Have you been successful in making this stop?