Should Google Introduce A Malware Filter?

One of the bigger complaints about Google's search ability is the amount of sites containing various amounts of malware or spyware or viruses still tend to permeate Google's search results. Many a horror story has been told about a users getting some type of computer infection from a site they've discovered on Google (or any search engine for that matter). On WebProWorld, a couple of suggestions concerning how Google should handle sites like this have popped up, like: should Google partner with Norton or McAfee in order to locate and block these sites from appearing in their SERPs, or should they embed something into their algorithms that remove these guilty parties? The responses to the suggestion indicated that even Google might not have enough resources to tackle this problem:

That would be nice, but ultimately it's not Google's responsibility. With the sheer volume of attacks and attackers coming from all angles, especially with the spyware issue, how could Google possibly keep up? Even with their resources, I don't think that's a fair request.

However, another suggestion provided an interesting idea that Google may actually be able to enact:

I think it would just be a complex issue and is likely to upset a lot of webmasters. Maybe some kind of optional filter like the "Adult" filter on image search would be a good way to go.