Slasher - I have only used one of the earlier versions of Nukenabber so cannot make a direct comparison. The ZoneAlarm does SEEM to be far more active. It appears that some sites request information from your machine or attempt to send same, in the background and I am seeing Zone Alarm activity here. For us mugs it is all relative anyway I suppose but I feel a lot more comfortable with this program than I did with Nukenabber.