The study found that 52% of the hard drives were unreadable or had been wiped of data, 48% contained some information and 11% contained personal data.
The amount of personal data found on the mobile phones and memory sticks was negligible, the report stated.
In all, the research found 34,000 files containing personal or corporate information on the devices. At least two of the hard drives contained enough information to enable the theft of the former owner's identity.
The residual documents included scanned bank statements, passports, information on previous driving offenses, and some medical details.
Four of the hard drives contained information about employees and clients of four organizations, including individuals' health and financial details.