It was a Facebook joke that went viral, but the creator behind the Storm Area 51, They Can't Stop All of Us event page was worried the FBI might knock on his door.

Key points: Storm Area 51 creator Matty Roberts said the Facebook event was originally created as a "funny idea for a meme page"

Storm Area 51 creator Matty Roberts said the Facebook event was originally created as a "funny idea for a meme page" Mr Roberts said he doubted an actual army would gather to run into Area 51 in September

Mr Roberts said he doubted an actual army would gather to run into Area 51 in September Facebook event has prompted fears that local businesses won't be able to handle a massive influx of tourists

The Facebook event saw 1.6 million people register as "going" with a further 1.2 million indicating they were "interested", created a huge buzz on social media with the rationale that if enough people turn up, there would not be enough guards to stop everyone from getting in.

In the details of the event, the creator suggested "if we Naruto run, we can move faster than their bullets. Lets see them aliens."

It has spooked Nevada hoteliers and even prompted the US Air Force to respond, telling the Washington Post Area 51 "is an open training range for the US Air Force, and we would discourage anyone from trying to come into the area where we train American armed forces".

Now the creator of the Facebook event has come forward, telling a CNN affiliate station he had declined interviews over fears the FBI might show up on his doorstep.

Millions have registered their interest in the Storm Area 51 event. ( Facebook )

"I waited for like three days and there were like 40 people and then it just completely took off out of nowhere," Matty Roberts told KLAS-TV in Las Vegas. "It was pretty wild.

"I was just like, the FBI's going to show up at my house and it got a little spooky from there."

Mr Roberts said he came up with the idea for the meme page after Area 51 whistle blower Bob Lazar — who claims he worked with an alien spacecraft while he was employed in one of Area 51's underground facilities — was interviewed on a Joe Rogan podcast.

Mr Roberts had previously told National Public Radio (NPR) using the pseudonym Val that he started the Facebook event because he "thought it would be a funny idea for a meme page".

There are no fences to Area 51, but plenty of warning signs for any intruders thinking of a dash into the restricted site. ( Shutterstock )

There are fears a huge influx of tourists to the region sparked by the Facebook event could put a strain on local businesses.

"Just about the time it went viral we filled up," Cody Phesing, who works at the Little A'le'inn motel, told the ABC.

"Today alone, since I came on shift, my phone has been ringing off the hook.

"I'll give it to you straight. We're freaking out. We honestly can't handle that many people."

Mr Roberts told NPR that he doubted an actual army would gather to run into Area 51 in September, but he said the Facebook event had put him in touch "with some pretty great people" to plan a safer event.