You could provide some secondary form of identification, rather than just an email address, like a scan of a drivers license or something like that if you want to volunteer an idea. It's only happened a couple of times in the last 13 years so we don't really have an official policy on how to handle it. Even if you are two different people with separate accounts you won't be able to do things like link to a file hosted on the other person's account. The most common reason people create multiple accounts is to get around our disk space limit, but since we offer a way to upgrade your account to get more storage it's better for you to do it the right way rather than risk suspension of all of your accounts.