Exercise 1 Send yourself a spoofed email from http://emkei.cz/
Exercise 2 Install the Google Chrome extension or use the online version of http://regex.info/exif.cgi. Also download and extract to your desktop the Exiftool from http://owl.phy.queensu.ca/~phil/exiftool/ View the meta data from images on the Internet or from your own collection.
Exercise 3 View personal data held on you by Google, Facebook and Twitter
Exercise 4 If you have an Internet enabled Android phone, register an account with https://ostel.me and try an encrypted VoIP call between two handsets.