Access to an e-mail account opens up access to all sorts of other information that could be used to steal someone's identity and drain bank accounts, open up credit cards, and even take out loans in their name.

It's not just personal information at stake in e-mail accounts. Use of weak password-reset security questions is believed to have allowed someone to access the Yahoo e-mail account of a Twitter employee last year and then use that to access the person's Google Docs account where there w...