Hi,
I know I'm a newbie and may have missed something. But if you created a list of the scam sites in the hosts file order. Then people could download (or add) the lists so that they can't access the sites by accident. - It just presents a blank page (because it thinks that the page is on YOUR PC (that's what the 127.0.0.1 means)..
For those who don't know, your hosts file (no suffix / extension) can be edited using notepad. It's normally stored in "C:\Windows\System32\drivers\etc\hosts". This is true for virtually all versions of windows, although it might be that the Windows folder is called Winnt or another name.
All you need to do is to add "127.0.0.1 " (you need the trailing space) in front of the site you want to "ban". Ie if the site is http://www.thisisascam.com you would enter 127.0.0.1 http://www.thisisascam.com
Similarly if the website is http://thisisascam.com then you'd enter
127.0.0.1 thisisascam.com
This is also useful as a anti-porn etc device if you've got kids, etc, etc. Though savvy kids might know about it (most won't).
There are ready made hosts files as well as lists of "unwelcome" sites you can download / add to your hosts file. Just Google it.
I hope that it helps
Cheers