US Immigration Enforcement
Since the Alien Registration Act of 1940, every non-citizen present in the US has been required to carry their documents with them at all times. This requirement applies to green card holders, business visa holders, foreign students, tourists, etc. — basically everyone who is not a US citizen. This law, despite being on the books for 85 years, has essentially never been actively enforced, but the current administration has made strict compliance a requirement in the US and created jeopardy in not doing so. Immigration officers may question any person they “believe” is a noncitizen, and can arrest without a warrant anyone who they have “reason to believe” (probable cause) is present in violation of law and who is “likely to escape before a warrant can be obtained.” In addition to being detained until their lawful status in the US can be confirmed, the offending person can be fined $130.00 or sentenced to imprisonment for not more than 30 days, or both. If a ticket is issued and the fine is paid, that act is an admission of the conduct, and individuals who are seeking citizenship in the future should ensure that they speak with an attorney familiar with the naturalization process before paying the fine.