What started as a disaster for KFC in the UK whereby it had to close hundreds of shops for - get this - running out of chicken (PS - KFC stands for Kentucky Fried Chicken!). But their apology which they did using ads in print starts off with a bucket that has FCK on it (add a U after the F and you get it). The text is also wonderful in terms of wording, including a mea culpa but also without being too servile. A great act of PR to clean up after damages!