# Detecting Suspicious Texts Using Machine Learning Techniques
## 3 A Novel Suspicious Bangla Text Dataset
### Suspicious Text and Suspicious Text Detection  
Suspicious Text Detection (STD) system classifies a text \(t_{i}cT\) from a set of texts \(T=\{t_{1},t_{2},\,...,\,t_{m}\}\) into a class \(c_{i}cC\) from a set of two classes \(C=\{C_{s},C_{ns}\}\). The task of STD is to automatically assign \(t_{i}\) to \(c_{i}\): \(<t_{i},c_{i}>\).  
Deciding whether a Bengali text is suspicious or not is not so simple even for language experts because of its complicated morphological structure, rich variation in sentence formation, and lack of defining related terminology. Therefore, it is very crucial to have a clear definition of SBT for making the task of STD smoother. In order to introduce a reasonable definition concerning the Bengali language, several definitions of violence, incitement, suspicious, and hatted contents have analyzed. Most of the information collected from the different social networking websites and scientific papers summarized in Table 1.  
\begin{table}
\begin{tabular}{p{142.3 pt} p{284.5 pt}} \hline \hline
**Source** & **Definition** \\ \hline Facebook & “Contents that incite or facilitate serious violence pose credible threat to the public or personal safety, instructions to make weapons that could injure or kill people and threats that lead to physical harm towards private individuals or public figures” [6]. \\ \hline Twitter & “One may not promote terrorism or violent extremism, harasses or threaten other people, incite fury toward a particular or a class of people” [31]. \\ \hline YouTube & “Contents that incite others to promote or commit violence against individuals and groups based on religion, nationality, ethnicity, sex/gender, age, race, disability, gender identity/sexual orientation” [32]. \\ \hline Council of Europe (COE) & “Expression which incite, spread, promote or justify violence toward a specific individual or class of persons for a variety of reasons” [33]. \\ \hline [PERSON] et al. & “Language that glorify violence and hate, incite people against groups based on religion, ethnic or national origin, physical appearance, gender identity or other” [7]. \\ \hline \hline \end{tabular}
\end{table}
Table 1: Definitions of hatted, incitement and violent contents according to different social networking websites, organization, and scientific studiesThe majority of the quoted definitions focus on similar attributes such as incitement of violence, promotion of hate and terrorism, and threatening a person or group of people. These definitions cover the larger aspect of suspicious content from video, text, image, cartoon, illustrations and graphics. Nevertheless, in this work, we concentrate on detecting suspicious content form the text contents only. Analyzing the contents and properties of these definitions guided us to present a definition of suspicious Bengali text as follows:  
\"Suspicious Bengali texts are those texts which incite violence, encourage in terrorism, promote violent extremism, instigate political parties, excite people against a person or community based on some specific characteristics such as religious beliefs, minority, sexual orientation, race and physical disability.\"