So this may partly be my fault, but who knows.. So I have an iPhone and my mother has an iPhone. While I was waiting for my iPhone 5s I sold my iPhone 5 and have been using a BlackBerry during this time. I don't care for regular texting, and I was lucky enough to have a lifetime Whatsapp subscription, so I thought I could get that for her as well. I had her log into my iTunes account on her phone and download Whatsapp. Afterwards, she signed out of mine and back into hers. All was well I assumed. Today, I get an email from Apple saying an app has been downloaded on a previously unused device from my account. My first thought was that someone managed to gain access to my account, but after talking to her, it was an app she just downloaded. The strange part is, she used HER credentials. So how the heck is this showing up under my account? If I go in to my purchase history, it shows this app. Any one have any experience with this and how to prevent it from happening in the future? This seems pretty ridiculous that if someone enters firstname.lastname@example.org with their password that it gets applied to email@example.com's account.