If you're disposing of old documents such as bank statements and tax forms, security experts recommend shredding the paperwork so it can't be used by identity thieves.
It's a practice everyone should be familiar with, since it may be the top recommendation for preventing identity theft.
However, many consumers and organizations are turning to a paperless world, and records once held in filing cabinets are now stored on computer hard drives.
But computers eventually get replaced, and old computers are donated, recycled, handed down or refurbished — often with personally identifiable information (PII) still on the machine.
Read more at: http://mashable.com/2013/04/26/how-to-erase-data/