P.S.
Just to let you know how easy this is, I followed a couple of links from the grc.com site, downloaded a few tools and hey presto, with only power-user knowledge of windows (no programming) I sit here armed with the same software used by these people.
And boy does it work. I loaded a trojan onto one of my home network PCs by binding it (terms I didn't even know until a few hours ago) to a picture attached to an email. Yep, you open a picture, you now have a trojan that barely anything can detect.
If I sent it to you, I could enlist your PC in a denial of service attack, browse through your files or just use you as a stepping stone to hack somewhere else with your pc as the culprit.
Pointless, but enlightening, I can now see the entire desktop of this 'sacrificed' PC, every mouse click, every file, every password stored in windows... I can even stream the webcam attached to it to this PC. And worst of all, the Norton Anti-Virus software installed on it hasn't got a clue what is going on.
I have a port scanner, IP scanner... took me about ten minutes to download and about an hour to figure out how to use it.
I had no idea what could be done until I started looking into it and although I have some (now out of date) IT experience, I reckon anyone with intent could be up and running within a couple of days.
It would take me an afternoon to take most web sites down or insidiously insert my software into them. This took me all of today to learn.
Flabbergasted.