A friend's analytics showed an amazing number of visits for a tiny site. While traffic was up, it did not lead to new clients. She fired the company she'd engaged for SEO/SEM because they kept raising their rates as traffic milestones were reached (hundreds of dollars a month).
Immediately after terminating that relationship, she noticed a 95% drop in traffic and panicked (see http://i.imgur.com/WwJ0vYo.png ). I was asked to fix it for her. One look in the referrers showed that this 95% all originated from China (ads.acesse.com) and was useless/fake (very few page views, very short durations). While we have no proof to support a lawsuit, the timing was too much of a coincidence to ignore.