A French researcher with the National Centre for Scientific Research (CNRS) was denied entry to the United States on March 9 while traveling to a conference near Houston. US immigration officers searched his phone at the airport and found messages in which he had expressed personal criticism of the Trump administration's research policies. He was reportedly accused of writing messages described by US authorities as 'hateful and conspiratorial' and told he was under FBI investigation, before being informed the charges were dropped and expelled from the country. France's research minister, Philippe Baptiste, said he was concerned by the incident and vowed to defend academic freedom and free research for French scientists.