There is actually another related, but potentially more serious flaw which has been posted on Reddit today:
http://np.reddit.com/r/webdev/comments/ ... rt/cqse31g
Full thread in context:
http://np.reddit.com/r/webdev/comments/ ... r_support/
It seems they've "fixed" the flaw in the past hour, but basically, you could reset anyone's password with just their basic information by redirecting the password-reset email to one in which you control.
If anyone has received an unprovoked password-reset email from Betfair in the past few weeks, then I strongly suggest you check your security information with them and change your password immediately.
It's no surprise that people keep having their accounts emptied. With shoddy programming like this in the most important "secure" areas of the site, it's almost inevitable that there are plenty of other similar issues around which the hackers are aware of but are not yet published.