Begun in 1997 to collect fraud and identity-theft complaints, the CSN now has more than 6.1 million complaints, including those about credit reports, debt collection, mortgages, and lending. The CSN has a 5-year data retention policy; complaints older than 5 years are purged biannually. Between January and December 2010, the CSN received just over 1.3 million consumer complaints, which the Federal Trade Commission has sorted into 30 complaint categories. The 2010 CSN Data Book is based on unverified complaints reported by consumers. The data are not based on a consumer survey. Of the complaints received during calendar year 2010, 54 percent were fraud complaints, 19 percent were identity-theft complaints, and 27 percent involved other types of complaints. Identity theft was the largest complaint category for calendar year 2010, constituting 19 percent of all complaints, followed by debt collection (11 percent); Internet Services (5 percent); Prizes, Sweepstakes, and Lotteries (5 percent); Shop-at-Home and Catalog Sales (4 percent); Impostor Scams (4 percent); Internet Auction (4 percent); Foreign Money Offers and Counterfeit Check Scams (3 percent); Telephone and Mobile Services (3 percent); and Credit Cards (2 percent). The complete ranking of all 30 complaint categories is presented in this report. Extensive tables and figures