A Chinese student studying in the United States was reportedly sent back home recently after arriving in the country with a bulletproof vest.

The student is studying at a “prestigious” university in Michigan and flew into Detroit where he got in trouble with customs officers, reports the World Journal, the largest Chinese-language newspaper in the US.

At a security check in the airport, the student reportedly informed officers that he was carrying a bulletproof vest in his luggage, causing them to search his belongings. The student said that they inspected and confiscated his personal computer and mobile phone. He believes his devices were sent off to counterterrorism investigators.

The student said he didn’t believe that he had done anything wrong, explaining that the vest was for his own personal use and that he had no evil intentions.

There are no restrictions on importing “soft body armor” into the United States, according to the US Customs and Border Protection website, but it’s unclear if the same holds true for more heavy-duty stuff. For its part, the TSA says that body armor “generally” is allowed in carry-on or checked bags, but that officers make the final decision on whether an item is allowed through a checkpoint.

The student reportedly had a gun license in Michigan. It’s unclear if that influenced the ultimate decision to refuse the student entry, cancel his US visa, and send him back to China.

News of the student’s repatriation has gone viral on Chinese social media with netizens arguing that bulletproof vests have become an essential travel item for those visiting the United States.

“Americans get to have guns, but we don’t get to have body armor. How are we supposed to avoid getting shot?” writes one Weibo user.

“All foreigners who come to China with face masks should be repatriated,” suggested another.

America’s problem with gun violence and mass shootings is widely-reported by Chinese state media and remains a worry for those Chinese nationals traveling to the country. Back in 2016, a 19-year-old Chinese exchange student at Arizona State University was shot to death by a woman inside her car following a fender-bender.

The tragic incident is said to have triggered many of her compatriots in the US to consider buying guns of their own.