Which of the following is NOT an example of illegal activity?

Buying concert tickets is not considered illegal activity because it is a common practice that involves the purchase of legal merchandise. Concert tickets are sold by authorized vendors or platforms, and purchasing them adheres to the legal frameworks and regulations established for ticket sales. This encompasses obtaining tickets for events, which is widely accepted and legally protected under consumer rights and sales laws.

In contrast, handling illegal drugs, prostitution or pimping, and gang activity all involve activities that are prohibited by law. Engaging in any of these actions typically violates criminal statutes, leading to legal consequences. Thus, the activity of buying concert tickets stands apart as a legitimate and lawful action.