Deviance
In response to Diana, I found Merton's thoughts on deviance as the result of cultural/socially structured (institutionalized) norms clashing important for understanding why people commit deviant acts. Although, this took me into another direction. I would argue that this clash of norms is what gives those in power the ability to define crime, thus, creating crime, criminality and criminals. People in institutions constructing these norms that conflict with cultural norms gives those in power the ability to legitimize their interests (norms) against others. For example, alcohol prohibition in the United States can be seen for some as a clash of culturally constructed norms and socially structured norms. For some cultures alcohol is used for celebration, with dinner etc. Putting a ban on the alcohol to protect the interests of those in power can be seen as a clash of cultural/social norms. From here, those in power are able to label those who consume alcohol during the prohibition as a 'deviant' act.
I definitely agree with your point on alcohol prohibition in the US because in some cultures in Europe for example alcohol is consumed at really young ages as a means of celebration, maturity and parties but is banned from people in the US until they reach the age of 21. It can be seen as a deviant act for under age drinking thus resulting into conflict with conforming to social norms because under age drinking can be seen as cool and most done in the age of high schoolers but because of the legal drinking age, those who do drink while they are under age can be deemed as deviant because they are not following the law. The issue of alcohol prohibition in the US can be seen as contradictory due to social norms that are broken because of the popular culture of under age drinking among teenagers in the US.
Similar to the age restrictions for alcohol consumption in the U.S. and the prohibition, the criminalization of marijuana can be examined in the same perspective. Like you've stated, people with power criminalize certain actions and things as a way to legitimize and prioritize their own interests over others and in doing so, create social/cultural norms that clash with the majority. The idea that marijuana is put on the same level as much harder drugs and resulted in countless arrests and imprisonment for the possession and use of it is baffling when we consider the fact that it has medicinal purposes and is much safer than alcohol and tobacco. This continued narrative of marijuana being dangerous and its criminalization can only be a result of those in power trying to protect their own interests. If we were to examine other parts of society we will only continue to find countless variations of this.