French researcher barred from US entry: "This measure was reportedly taken by American authorities because the researcher's phone contained exchanges with colleagues in which he expressed a personal opinion on the Trump administration's research policy"
https://www.lemonde.fr/international/article/2025/03/19/etats-unis-un-chercheur-francais-refoule-pour-avoir-exprime-une-opinion-personnelle-sur-la-politique-menee-par-l-administration-trump_6583618_3210.html