Google appears to be making strides in the war against account hijacking. The ads, search and webmail giant recently announced that it had reduced takeovers by 99.7 per cent since introducing tighter security procedures.
Improved spam filtering meant spammers switched to more aggressive account takeover tactics over the last two or three years or so. This meant 419ers and others tried to hijack email accounts before sending fraudulent messages to potential marks, usually the friends and contacts of an account hijacking victim. Using auto-generated newbie accounts no longer works because messages from these accounts were routinely blocked.
Email account hijacks often follow either phishing campaigns or database leaks from insecure websites. Because many people make the mistake of re-using the same password across different accounts, stolen passwords from one site are often valid across many others.
Source: The Register