David Becker/Getty Images

A joke to "Storm Area 51" on Sept. 20 went viral over the summer and has the city of Rachel, Nevada, bracing for people on the hunt for aliens and is now a weekend party called Alienstock. The county district attorney, however, says he could take action against those responsible for the stunt.

Dylan Frehner, Lincoln County district attorney, says he's considering pressing charges against event creator Matty Roberts and Facebook, according to a Monday report from the Las Vegas Review-Journal. The possible charges include a gross misdemeanor of publishing a matter in breach of peace or other crimes, which could result in a $2,000 fine and up to one year in county jail.

"Anybody who is promoting any illegal activity, we will be seeking to possibly prosecute," Frehner told the Review-Journal.

Friday's "Storm Area 51" event has more than 2 million people on Facebook saying they're going to the event, and some are already in Rachel. Businesses in the town have already seen an increase of tourists coming from around the world, according to a Thursday report by the Associated Press. Local officials have begun preparations, but some are concerned that those coming to see what the Air Force base known as Area 51 has inside could put a strain on resources.

Facebook didn't immediately respond to a request for comment.

Originally published on Sept. 19 10:50 a.m. PT.

Update, 1:51 p.m. PT: Adds background details.