3) Never, ever enter important credentials to a site you didn't open from a bookmark. Sure, but most users are careful when they first login to a site like gma

3) Never, ever enter important credentials to a site you didn't open from a bookmark. Sure, but most users are careful when they first login to a site like gmail, but then leave the tab open. Mentally, you know you only opened your gmail tabs from a bookmark, so any gmail tab already open must be safe. That's what the attack plays on - you're not on your guard, so don't check the URL.