Whatthehell was he doing in NK?

I am fine with people going where ever they want when ever they want but some judgement might have been brought to bear.

I did a quick search basically asking the question I ask above.  The best explanation seemed to be the BBC.  Which included this quote -

He went through a China-based company called Young Pioneer Tours, which boasts of providing "budget travel to destinations your mother would rather you stayed away from".

You know what, sometimes you really should just listen to your mother.  I hope this event discourages others from thinking, wow, it would be kewl to go to the most dangerous country on earth.

In a press conference on February 29, 2016, Warmbier repeated his confession that he had stolen the banner to take back to the United States.

He said he stole it for the mother of a friend who wanted it as a souvenir to be hung on the wall of a church in his hometown of Wyoming, Ohio. He said that she offered him a used car worth $10,000 as payment, and that if he was detained and didn't return, $200,000 would be paid to his mother in the form of a charitable donation.

Warmbier said he accepted the offer because his family was "suffering from very severe financial difficulties".[30] He also said he was encouraged in committing his act by his desire to join the Z Society, a "semi-secret ring society" and philanthropic organization at the University of Virginia.

Warmbier read the following statement at his trial:

    I never should have allowed myself to be lured by the United States administration to commit a crime in this country. I wish that the United States administration never manipulate people like myself in the future to commit crimes against foreign countries. I entirely beg you, the people and government of the DPR Korea, for your forgiveness. Please! I have made the worst mistake of my life! Please! Think of my family.[31][32]