Elon Musk and Melania Trump both overstayed their visas and aren't supposed to be here. Elon is known to have violated the terms of his visa, which under the current administration's theory of immigration renders his citizenship void and requires him to be banned from the U.S. for at least 10 years.

Nobody knows what Melania was doing between the time she arrived and the time she met Trump. She only had a handful of photoshoots shortly after she arrived, and then nothing for 3-4 years until she met Trump at a social event.