A new law has just been put in place in South Korea this week that'll see offending players handed hefty fines and maybe even up to two years in jail for account boosting and similar practices.
As highlighted by industry insider Daniel Ahmad on Twitter, and as explained by this translation on Reddit, the act of boosting is defined as the "act of playing a client's account in his or her stead and raising his or her points/achievements."
According to the translated document, people will be "prosecuted depending on whether the game company authorized it, whether there was payment, and the frequency of the act," so it's not like doing it one time will land you in the slammer, although it's clear that the authorities are trying to dissuade people from the practice.
The law, which was first outlined back in June 2017 and passed last December, came into effect yesterday, and the maximum punishment is a fine up to $17,300 or, in the worst cases, up to 2 years in jail. It's also worth noting that past indiscretions won't be counted, and, of course, if you're not based in South Korea, this won't affect you at all.