I have an iPhone, which have been carried from Canada to Vietnam. I used it for accessing my yahoo account in order to check my e-mails. When I finished, I didn't log out but leave it idle. A few days later, I couldn't access to the account by a computer. However, my iPhone was still kept logging in the account and it can be accessed normally. After then, I tried changing my password but could not succeed because the password had been changed. Since I wasn't able to remember its recovery information, I must have lost my account. I want to ask if there was something wrong with my iPhone, if I was tracked or if my account was hacked?