Who is 'Green Shirt Guy,' the Arizona man who went viral for laughing at Trump supporters?

An Arizona man, identified originally as "Green Shirt Guy," became an overnight internet sensation.

But who is he? How did he go viral? And most importantly, why are people so obsessed with him? That last question is tough to answer, but here are the basics.

Green Shirt Guy, whose real name is Alex Kack, is an activist and comedian who went viral for his reaction to a pair of Trump supporters at a city council meeting in Tucson, Ariz., Tuesday.

Kack was caught on video laughing uncontrollably as the supporters — a man and a woman — protested the town's decision to place a "sanctuary city" measure on the ballot for an upcoming meeting in November. The vote would give Tucson a chance to become Arizona's first ever "sanctuary city."

The clip, first posted by KVOA News reporter Nick VinZant, shows the man and woman screaming and holding up a sign that reads, "Respect our laws or we will deport you."

Many attendees can be heard booing the man and woman, but Kack, who is sitting nearby, is seen laughing so hard he has to clutch his chest.

Following the meeting, Kack instantly became an internet sensation. The original video has more than 12.6M views as of Friday afternoon, and even celebrities like Mark Ruffalo, Chrissy Tiegen and Patton Oswalt have tweeted about Green Shirt Guy.

In the days following the meeting, social media feeds were filled with memes, comments and support for #GreenShirtGuy.

Kack later explained his laughter in an interview with KVOA.

"People really took time out of their day to go interrupt a city council meeting to just yell crazy, ignorant, racist, hate-filled stuff in the most absurd manner they could possibly do it," he told the news station.

So what is Kack doing when he's not laughing at anti-immigrant protestors? Mashable reported that the 28-year-old is a field organizer for the Peoples Defense Initiative, a progressive, grassroots activism group.

As for his thoughts on his new celebrity, Green Shirt Guy said he thinks laughter helps people cope with today's political climate.

"It's an incredibly dark time and there is a lot of hateful rhetoric that’s happening nationwide right now, but ultimately the majority of this country — regardless of their political affiliation — understands that the loudest voices happening right now are kinda ridiculous," Kack told KVOA. "And I think the laughter is resonating because that's how people feel right now."