will not be here anytime soon. [ laughter ] >> roy choi: yeah, i mean, so that's when all the stuff started to go down. >> anthony: roy choi is a second-generation korean american. he lives in los angeles. he's the owner/operator of four groundbreaking and much loved food trucks, among the first to harness the strange and terrible powers of social media to alert customers to where to find delicious food. >> roy choi: this was the command post. from here, you know, you could look and you could see if fires were going on. >> anthony: when the los angeles riots happened in 1992, roy was 22 years old. and this plaza's rooftop played a central role for koreans defending their town. but let's back up a bit. after the immigration act of 1965, thousands of koreans began arriving in l.a. the first to arrive were mostly middle-class, college-educated, hoping to make a lateral move into american society. but unless you had a medical or engineering degree, that turned out to be tough. they found work as merchants, store owners, opened liquor