North Korea has never hesitated to mete out harsh punishments for foreign missionaries, illegal border crossers or anyone involved in acts it considers to be hostile or subversive. But until a few years ago, hardly any foreign tourists were arrested or detained for much more than questioning, though North Korea may be lowering its bar.

Here are some recent cases involving foreigners, mostly Americans, who arrived on tourist visas — and often their own agendas — but wound up in jail:

MERRILL NEWMAN — In 2013, North Korean authorities detained and then deported 85-year-old Merrill Newman, an American tourist brought into the country by Beijing-based Juche Tours. Newman, a Korea War veteran, was held for nearly two months for his wartime involvement in training anti-North Korea fighters. He later told his story in an e-book in which he claimed North Korea sent the Swedish Embassy, which handles U.S. consular affairs in North Korea, a $3,241 bill for the time he spent in detention at the Yanggakdo Hotel. He says he declined to pay.

JOHN SHORT — Short, a 75-year-old Australian missionary on a tourist visa, was taken into custody for distributing Biblical materials on the Feb. 16 birthday of the late leader Kim Jong Il in 2014. He was deported the following month. As is the general rule in North Korea, Short's release followed a written confession and apology. He recanted after he left the country, which is also typical.

JEFFREY FOWLE — After getting into North Korea as a tourist, Fowle was arrested in May 2014 and eventually sentenced to 15 years in prison for leaving a Korean-English Bible at a provincial club frequented by locals. He was in North Korean custody for about six months before being flown out on a U.S. government aircraft sent to retrieve him. After his return to the U.S., he said he deliberately planted the Bible because he wanted to spread Christianity in the North.

MATTHEW MILLER — Miller, a California native, was arrested at Pyongyang's airport on April 10, 2014, after tearing up his tourist visa and later sentenced to six years of hard labor for espionage and other charges. He has told the media he wanted to get arrested, though his motives remain unclear. He stayed in custody until U.S. spy chief James Clapper flew to Pyongyang in early November that year to retrieve him and American missionary Kenneth Bae, who was already serving a long prison sentence for anti-state activities.