Confidentiality Issues Involved in Collecting Data Over the Internet Include

Confidentiality issues involved in collecting data over the Internet include

A) Some data collection software automatically collects information such as email addresses, so it might not be possible to assure participants that their data will be anonymous.
B) Even when personally identifying information is removed from data collected from social media sites, the remaining information could be pieced together to identify participants.
C) The computer files in which data are stored may not be totally secure.
D) all of the above