1. Naive bayes.
http://www.nltk.org/_modules/nltk/classify/naivebayes.html
2. SVM.
http://www.nltk.org/_modules/nltk/classify/svm.html
3. Code contracts (2010).
http://research.microsoft.com/en-us/projects/contracts/
4. EU data directive 95/46/ec, February 2014.
http://eur-lex.europa.eu/
5. Facebook photo leak flaw raises security concerns, March 2015.
http://www.computerweekly.com/news/2240242708/Facebook-photo-leak-flaw-raises-security-concerns