Two travelers from Britain were prevented from entering the US last week after Homeland Security officials feared one of the pair, 26-year-old Leigh Van Bryan, might follow through with one of his tweets. Prior to leaving the UK, Leigh had tweeted that he was going to “destroy America.”

The offending tweet read, “Free this week, for quick gossip/prep before I go and destroy America?”

Even though Leigh explained to officials at Los Angeles international airport that the word “destroy” in this case was British slang for “party”, they were having none of it and threw him and his friend, Emily Bunting, 24, in a cell for 12 hours before sending them back to Europe the following day.

Further complicating matters was another tweet—a quote from the hit comedy Family Guy—which suggested he might “dig up Marilyn Monroe”.

According to Leigh, that tweet had officials looking through his baggage for a shovel and asking his friend whether she was going to act as a lookout while Leigh dug up Monroe.

“I almost burst out laughing when they asked me if I was going to be Leigh’s lookout while he dug up Marilyn Monroe,” Emily told the Daily Mail on her return to the UK. “We just wanted to have a good time on holiday. That was all Leigh meant in his tweet. He would not hurt anyone.”

Leigh said he tried to explain to officials that they’d got the wrong meaning from his tweet, but they were having none of it.

Prior to their flight back to the UK, the pair were handed charge sheets relating to their ordeal. Emily’s read: “It is believed that you are traveling with Leigh Van Bryan who possibly has the intentions of coming to the United States to commit crimes.”

The incident has echoes of a case in the UK in 2010 when a man by the name of Paul Chambers joked on Twitter that he was going to blow up an airport. He was subsequently convicted and fined for sending a menacing electronic communication.

Both stories highlight the fact that, depending on the words they use, some of our tweets are being flagged up and looked at by the authorities, and that if we’re not careful, even innocent throw-away lines might end up being misconstrued, leading to problems we couldn’t have envisaged when we tapped out the tweet.