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Metal detectors and luggage scans aren’t the only way U.S. Customs and Border Protection identifies national security threats. The agency also keeps close tabs on social-media sites, and it allegedly detained two British tourists after a questionable Twitter conversation, according to British newspapers.

A week before heading to Los Angeles, Leigh Van Bryan, 26, and Emily Bunting, 24, tweeted with friends about their vacation plans. “Free this week for a quick gossip/prep before I go and destroy America?” Bryan wrote to Twitter user @MelissaxWalton. “3 weeks today, we’re totally in LA p—ing people off on Hollywood Blvd and diggin’ Marilyn Monroe up!” he wrote to Twitter user @ELB_1987.

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But their seemingly humorous tweets didn’t go over well with airport security. According to the Daily Mail, Bryan’s Twitter conversations flagged him as a “possible threat,” and he and Bunting were taken aside by armed agents at Los Angeles International Airport and had their passports confiscated. They were reportedly questioned for five hours, put in a van with illegal immigrants and held overnight on suspicion of planning to commit crimes.

The pair tried to explain to border patrol that destroying is British slang for partying and that they were kidding about desecrating Marilyn’s grave — the tweet, they said, was a line from the show Family Guy.

“The officials told us we were not allowed into the country because of Leigh’s tweet. They wanted to know what we were going to do,” Bunting told the Daily Mail. “They asked why we wanted to destroy America and we tried to explain it meant to get trashed and party.”

And though words such as destroy, smash, blaze and rage may translate into a big night out for 20-somethings, U.S. immigration officials didn’t make an exception.

A U.S. Customs and Border Protection spokesperson confirmed that two individuals in a similar circumstance had been denied admission to the U.S., MSNBC reports, but the agent denied details citing privacy laws. According to the Daily Mail, the pair have been told they can’t return to the U.S. until they apply for visas from the U.S. embassy in London.

So much for a smashing good holiday.

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