1script - 2:43 pm on Jun 27, 2012 (gmt 0)

you *could* try changing the URLs of the pages that are linked to, which would instantly render those backlinks invalid.

Nope. I played with this extensively (pre- and after-Penguin) trying to remedy the issue of bad links from WordPress themes I wrongheadedly sponsored back in 2009. 404-ing or 410-ing the link target URL does nothing to improve the ranking (or remove penalty) of the site overall.

Google seems to be taking nothing short of actual removal of links for a solution. Even then it does not always work because they are not crawling bad sites fast enough - the recovery may be very painfully drawn out because it can take them ages to re-crawl all of the URLs that contained bad links. I think most of the really bad sites you would want your links out of have very small crawl budget to begin with. I am still seeing links that were removed 120+ days ago from such sites.

I'm convinced noone at Google actually reads our reports of the number of links we were able to remove. They probably simply have no time in this post-Penguin world because thousands of webmasters send them those every day. They are just waiting for the links to "naturally" fall out of their index. In late 2011 I was able to get some back-and-forth regarding these links with Google through RRs and emails but since Penguin there's not a peep back. They got themselves buried under a mountain of similar requests for bad links removals and simply stopped processing those (my conjecture of course).