Looking for information from someone who's recently visited Korea as a tourist.
With regards to visitors buying a SIM card for local use, I've noticed some countries are totally laissez-faire. You just hand over some cash and get a SIM, like buying a chocolate bar. Nobody asks or cares about your name or anything else.
In contrast, other countries have high paperwork and identification requirements.
(I guess the most extreme is countries like India, where SIMs are highly controlled and foreigners can't get a SIM.)
What is the situation in South Korea? Surely a traveller here has visited lately???