On March 9, 2025, a French researcher who works in the space sector for CNRS, France’s national scientific research center, flew to the United States for a conference near Houston. He was refused entry and sent back to France after border officers examined his phone and computer. The two governments have never agreed on why.
What is known
The researcher has not been named publicly. The incident became public on March 19, when France’s minister for higher education and research, Philippe Baptiste, described it in a statement to the news agency AFP. The U.S. Department of Homeland Security responded over the following two days.
Two accounts
The French minister said the researcher’s phone contained exchanges with colleagues and friends in which he “expressed a personal opinion on the research policy pursued by the Trump administration.”
A Homeland Security spokesperson said the researcher had confidential information from Los Alamos National Laboratory on his device, in violation of a non-disclosure agreement, and that any claim he was turned away for his political views was “blatantly false.”
Timeline
- March 9, 2025: the researcher is refused entry and returned to France.
- March 10–14: a major planetary science conference takes place near Houston. News outlets have inferred this was his destination; it has not been confirmed.
- March 19: the French minister makes the incident public.
- March 20–21: U.S. officials reject the French account.
What is not clear
We found no later reporting that reconciled the two versions. Some French media reports, citing unnamed sources, said officers described the messages as hateful and that an investigation was mentioned and then dropped. U.S. officials have not confirmed that. The airport where he arrived was not confirmed either.
Why the story drew attention
U.S. Customs and Border Protection has long asserted the authority to inspect electronic devices of travelers arriving at the border, and a visitor who is not a U.S. citizen can be refused admission. The case prompted discussion among researchers and business travelers about what they carry on their devices when they cross a border.
Sources
This article is a summary of publicly reported events, prepared for general information. It is not legal advice and does not take a position on the matters described. Immigration rules and court rulings change often, and every situation is different. For advice about your own circumstances, please speak with a licensed immigration attorney.
