Google is finally doing something about spam. The noise is growing louder about the spam gumming up many Google queries, and about content farms like Demand Media (content farms and spam aren't the same thing, but some people feel they are). Some people even think it might erode Google's dominance over search.

The latest move is that Google might allow you to blacklist entire domain names (like businessinsider.com) from searches. Once you add a domain to your blacklist, pages from that domain wouldn't appear in your search results. In time, Google could use the domain names people blacklist as a repository of spam services. (Search Engine Land)

Of course, this could spell trouble for Demand Media, the biggest of the content farms, which has many media sites, but a few huge ones like eHow. Many people obviously feel that eHow and other Demand Media sites are little more than spam, and are going to blacklist it.

It's unlikely that an opt-in feature like this could become widely used, as most users don't pay attention to which domain name they're on (really), but depending on how they implement it, eHow being blacklisted by a small but ardent minority could erode its search ranking, which would deprive it of vital traffic (and therefore money).

And Google is doing all of this as Demand Media is getting ready to go public, which means it can't respond to all these third party allegations about it being spam, given legal SEC requirements about "quiet periods" around IPOs.