It has been found that the prosecution did not investigate B.I over the doubt about drugs purchase
in 2016 because he wasn'ta famous celebrity at that time. In other words, the prosecution has admitted to a poor investigation into the case. They focused on more famous celebrities.

CBS reported the phone conversation with an official at the Suwon District Prosecutors Office on 18 June. They said, "When the investigation report was handed over, the prosecution was investigating YG's top celebrities. Back then, B.I was not a very famous celebrity."

K-netz reacted negatively to this response of the prosecution and criticized the prosecutor's poor investigations. 

Fans also got angry with this answer and they expressed their reactions such as; "How lucky people in Korea other than artist can do anything what they want because Korea's law only for famous one."  "So, now he is famous and then they decided to ruin his career?".
"In 2016 B.I, who was not even known for not investigating because he was not a celebrity, has reached enough popularity for the police investigation now. What K-Drama is?" and "Look at the system of the country, from the police to the prosecutor, they all enjoy darkening people's lives after they've accomplished something."