That's a great point. Imagine if one of these sites got hacked. A hacker could literally walk away with a list of emails, each exchange on which that person has

That's a great point. Imagine if one of these sites got hacked. A hacker could literally walk away with a list of emails, each exchange on which that person has an account, and a list of assets. Time to sort by most valuable account, and go spear phishing...