Despite our (usually modest) efforts to protect our personal information, thieves and hackers are constantly accessing our records. These data breaches have soared since 2005. Although crooks still account for most invasions, many of the largest breaches are now made by "hacktivists"—individuals or groups who are angry about a company or organization's actions and expose its records as a way to protest or to strike back. Despite recent media coverage of electronic espionage, however, snatching a laptop and even dumpster diving are still on the list of ways that snoops get your data. Here's the ranking of the methods they use, compiled by the Open Security Foundation in Glen Allen, Va.

— Mark Fischetti

Data Breach Rankings
Type of Data Breach Percent of Cases
Stolen laptop 7%
Hacked computer or server 16%
Scraped from the Web 12%
Fraud or scam 10%
Document found in trash or unattended 7%
Stolen computer 6%
Snail mail exposed or intercepted 5%
Email exposed or intercepted 4%
Stolen document 3%
Lost media found 3%
Lost document found 3%
Lost computer drive found 2%
Stolen computer drive 2%
Virus 2%
Other 8%

» Read more about ‘Data Theft: Hackers Attack’ in the October 2011 issue of Scientific American.

Source: “The Health Costs of Inaction with Respect to Air Pollution,” by Pascale Scapecchi, Organization for Economic Cooperation and Development, Environmental Working Papers, No. 2.