Check the edit history and comments on https://stackoverflow.com/questions/8327162/how-to-fix-long-urls-in-magento-for-layered-navigation-seo-practice
In my opinion this is not a valid reason to use a short url - if you don't want your page to occur in your question, you don't put a link to it in there but create a testcase on another domain.
Especially when browsing SO at work people usually want to know if a link looks safe or points to a well-known shock site (or any other NSFW site) and IMO that's of a much higher value than "people should now know that the developer of site xyz asked others for help".