While surfing yesterday evening one of those PC optimizing software offers latched onto my Internet Explorer and wouldn't let go. You know the type. All of a sudden a dialog box opens on the screen wanting you to download the product. The box won't take "no" for an answer and keeps coming back no matter how many times you X it out. Finally shook loose from this thing. Not sure how I did it. What is this kind of pest called? Is it something that my NOD should have intercepted? If not, what is the best defense against these things?