Cosmopolitan Magazine Sweepstakes entry warning, Internet

I entered an online sweepstakes for Cosmopolitan magazine.  When I hit enter, it said thank you for your order.  I did not order anything.  I called customer service and they said they would cancel the order.  I also found the link on their site to cancel the order, which I did do.

This was a month ago.  Today, I rec'd their magazine in the US Mail.  I checked their website and found my account and it did say it was canceled.  I printed out that page.  They did cancel the account, but I find it very questionable for them to create an account from a sweepstakes entry.  Anyone with someones email address and mailing address can enter their sweepstakes.  This shouldn't be allowed at all.  They should have to email the entrant to make sure they ordered their magazine.