Computer users are often strongly recommended to use security products to make their internet experience a safer one. Developers also often adopt extra security measures to provide advanced data protection. Every now and then, these security products and additional security measures themselves become a source of serious security and privacy risks. In this seminar, I will talk about our evaluation of some of these products: a selected set of anti-virus applications, enterprise network appliances, parental control solutions, and top mobile apps. Our findings uncover several critical design and implementation flaws, and question the current best-practice of continued use of these security products and measures.