The Scunthorpe Problem The Scunthorpe problem (or the Clbuttic Mistake) is the unintentional blocking of websites, e-mails, forum posts or search results by a spam filter or search engine because their text contains a string of letters that appear to have an obscene or otherwise unacceptable meaning. Wikipedia Examples would be: shitake mushrooms, Herman I. Libshitz, magna cum laude, Arun Dikshit.