rainborick - 3:42 pm on Jul 6, 2011 (gmt 0)
My concern would be that when you redirect such links, you're essentially "adopting" them. They never have any PageRank to speak of, and certainly no trust or authority value, so the upside is negligible. And it wouldn't make sense for these 404s to hurt your site since they originate from other domains. With all of the poorly written scripts out there, I don't believe that the search engines count the bad links they create against the target sites UNLESS you redirect them. So if you're even slightly concerned about the origin of these links, I believe it's best to simply let them go 404.