The bloggers themselves and Google are the only ones that can fix this. If the Google algorithm would not be so dependent on quantity of back links people would not waste their time doing this. It’s the same reason people put their sites in their signatures – more back links. If it isn’t crystal clear to everybody, links are the way to get results in Google.
From what I’ve seen, for every site you may get Google to remove there will be thousands ready to take their place with the same tactics because they know they have no chance of competing otherwise. Because they don’t wish to or can’t wait the amount of time it takes in the natural aging of a site. It’s fine to say they can compete but what is left out is that in Google it will be a good period of time before they can do so.
I look at this as manipulation rather than spam. Spam is the unsolicited garbage you get in your email every day. What does it matter to the searcher how the site ended up in the top ten as long as it’s relevant to their search query? As for the blogger, they own their site. If they don’t wish to have tons of links for viagra, online casino, car loans etc. it is within their power to do something about it. The blogs where I see this is where the owner hasn’t been around in a long time. Any popular blog with lots of current traffic doesn’t seem to have this problem.
There is no such thing as getting enough people wishing to link to your gambling site (one way) because you have “quality content” and bringing your site to the top of the SERPS. (well, maybe if you’re site has been around 5 years) It’s all manipulation, the blog links, the message board links, the bought links, the interlinking of hundreds of your own sites, internal linking, the directory links, reciprocal links, all of them. As long as Google allows it will continue. It use to bug me a little but now I just figure its another way of competing and my time would be better served by working on my own sites. Like I said before, it may not be without risk, now or in the future. I’d prefer to have a lot of these blogs available for advertising rather than take the chance on being shut out because I pissed them off.