Home Depot. JPMorgan Chase. Neiman Marcus. University of Maryland. Over 600 data breaches in 2014, against a broad range of businesses - financial, retail, and even universities.
Why is your identity at risk? Because criminals want to make money. Big money. There were 12.6 million U.S. victims of identity theft in 2012, and it is estimated to have cost them 21 billion dollars. (source: https://www.erieinsurance.com/-/media/Files/IdentityTheftinAmerica.pdf )
Criminals can use information about you (that they steal from companies on the web) to pose as you and open lines of credit, apply for and get credit cards or take out bank loans in your name, etc. They can glean the required information from places like banks, retailers, universities, and social web sites. (you don't have your birthday, maiden name, mother's name, address, birth city, pet's name, etc., on your Facebook page, do you?)