I can not put a name to a customer but they spent millions to port their data warehouse to Hadoop and 1 year later rolled everything back to the Db2 again since their results were not matching and the data was getting lost. This is a classic example of misuse of the technology. This stems from the fact that even enterprizes who earns money by using the software tend to get into this murky water of jumping the band wagon of the tendency to not pay for the software and instead use open source. People generally site example of Google, FaceBook or others but little they forget these companies employ best of the brains who are highly paid and they have the ability to get things done using the open source.
Dr. C Mohan gave this talk sometime back on Big Data: Hype and Reality and this echoed very well with my experience.