unlawful dumping (e.g. of garbage)
illegal entry (into a country); illegal immigration
tort; illegal act; illegal activity; offence; offense
illegal residence (in a country); illegal stay; illegal overstaying (of a visa)
illegal immigration; illegal immigrant
illegal possession; unlawful possession
illegal employment; illegal work; unauthorized labor
unlawful detention (of shipping); unlawful occupation (of a house or land)