Content analysis is an established and effective method for research in the social science and, despite what many think, it has been around for quite some time. It has also tremendously benefited from ICT and the growth of computing power, as computers have proved to excel in the dull routine of scanning texts for keywords. But content analysis has become ubiquitous with the advent of the Internet, particularly emails and Web sites. Keyword search, a pivotal element of content analysis, is the most widespread feature of many Internet applications, from search engines to password-cracking programs. Consequently, it has become a central concern for cybersecurity. This chapter investigates some of the most important applications of content analysis on the Net and discusses its increasing essential position in many areas of cybersecurity.