The Identity Theft Resource Center reports 102 data breaches in the U.S. since Jan. 1, 2005, potentially affecting more than 56.2 million individuals. Most of the incidents could have been prevented with safe data handling practices, for example, sending postcards with Social Security numbers on them or requiring students to place name and SSN on rosters that are passed through classrooms or placed on papers or tests. See a most updated list of 2005 Disclosures of U.S. Data Incidents (PDF). An interesting observation is that a lot of these incidents happened in universities.