1script - 5:09 pm on Apr 18, 2012 (gmt 0)

Redirects - Acquiring related websites to redirect to your site would be a method to try to manipulate your search engine rankings. Why else would one do it? The proper thing would probably be to keep that website as its own entity and develop it on its own.

Terminology apart, the issue of redirects hits close to home for me.
I'm one of those people that never seem to settle on a good name for a site. Most of my sites have moved at least once in their lifetime and some moved more than that. I do still keep old domain names and I do redirect all those to current locations. I'd say it would probably be considered a fairly benign use of redirects if I could be sure Google's quality team has a millisecond to stop and think about it when they consider a site.
Anyhow I see you put redirects like this rather high on your list. At the same time it's one of the most easily fixed issues I can think of. Do you think it makes sense to remove such redirects from old locations?
Cheers!