Bad Sites Block

[#1]

I don't know if its possible, and I'm sure some people would not want it (so make it on/off switchable) but how about a filter, along the same lines as the IWF filter, that blocks people from accessing sites which are known to contain just trojans and virii and other nasty stuff which may harm ones computer?
One example would be the flashplayer which contains a virus that steals login information, it's currently hosted on a site which I won't link to, but if that was stuck in a database on PN's site and anyone got the "you need the latest version of flash player" warning, even though you have the latest version, you could click on the link (if you were not really all that aware that clicking links is bad) and PN itself would block the website, would that be possible?
It could also be used to add known phishing sites, kind of adding an extra layer of protection.
I use Kaspersky, and I tend not to visit sites which may harm my computer, but even with these things I'd love an extra layer of protection.

[#2]

Paranoia.

[#3]

One commercial product such as you mention is Aladdin. A trial of an earlier release of this was conducted in spring/summer last year (launch and conclusion links).
I think the general conclusion was that the product was effective (worked) though finer control (e.g. through whitelists and blacklists) was needed than that available at the time. A "user agent" allowing consumers to control filtering and access logging to suit their specific needs was under development  (about to enter beta test as the trial ended).
Quoting from the concluding blog:

Quote

Performing this trial has helped us identify that this type of service is one which would offer great value to our customers, although there is still plenty of work for us to do on aspects of the product before we are in a position to fully launch it. We’ll let you know as soon as we have further information about how and when we plan to launch our Parental Control product.

I am not aware of any update from Plusnet on the statement in the last quoted paragraph.
David

[#4]

As an alternative, if you're using Firefox, you could use the NoScript add-on to control much of this yourself.
http://noscript.net/
"add-on allows JavaScript, Java, Flash and other plugins to be executed only by trusted web sites of your choice"
Cliff