For a pitcher, the pickoff throw to second base is a delicate, dangerous dance. You need to pivot 180 degrees and whip an accurate throw to a teammate you trust has moved to the bag. If you fail, not only will you look like a complete idiot—you will probably wind up with a baserunner 90 feet closer to home plate.
And if you fail as spectacularly as Lim Chang-yong of the Korean Baseball Organization's KIA Tigers, you might end up in trouble with Johnny Law. Lim was suspended three games and ordered to complete 120 hours of community service after tossing a stupendously bad (or perhaps even intentional) pickoff throw just over the head of baserunner Oh Jae-won in a game against the Doosan Bears.
Lim took his time on the throw, had a clear view of the runner, and there wasn't a fielder in sight, which has led some to believe he deliberately threw at Oh, who responded with a look of simultaneous rage, terror, and relief before collecting himself and confronting Lim at the mound. The umpires intervened and play continued.
Hopefully Lim has learned his lesson. Throwing at baserunners already in scoring position is wrong—at the very least, it's pretty terrible strategy.