Even if you are careful not to post private information, you might not realize how much metadata becomes available whenever you post something online.
Metadata is information that is contained in files such as photos and status updates on social networks, but is not visible when looking at the content, so many people are not aware that it exists.
This is the second in a series of blog posts debunking some common misunderstandings about online privacy. The images used in these posts have been adapted from a tutorial given by Gerald Friedland at ACM Multimedia in Nara, Japan in October.
Many people assume that their online communication is private. While one-to-one communication online may be intended as private, if it is not encrypted, it is not private. Whenever information is sent online, there is the possibility that someone other than the intended recipient can view it. Encryption helps prevent the information from being seen by a third party, so sensitive information (such as emails, chat, or video calls containing information that you want to keep between you and the recipient) should always be encrypted.
Even if you are careful not to post private information, you might not realize how much metadata becomes available whenever you post something online.