An illegal alien is a person who is physically located in a country or area where he or she is not legally permitted to be. He or she need not intend to permanently reside in a country to be considered an illegal alien. People may choose to become illegal aliens when seeking work, fleeing poverty, escaping war, or any other number of reasons. Illegal residents are a subject of much concern because they are at a heightened risk of exploitation or death and because they are thought by some to cause economic or social problems.
Some countries take steps to forcibly remove illegal aliens, particularly when they pose a perceived danger to society. Other countries take a more lax approach, either because the resources required to find and deport an illegal alien are too great, or because the illegal alien does no harm. Even without legal sanctions, a person who is not a legal resident or visitor may find that a routine evaluation of documents can result in deportation. It is therefore usually not easy to live as an illegal alien.
While a tourist without proper clearance can be considered an illegal alien, the term is almost always used for people who intend to work or take up residence in a country. Overstaying a visa often results in fines or other light punitive measures, but is typically not met with the same level of punishment reserved for people with an intent to work or live illegally in the country. In either situation, though, there is a likelihood of deportation.
Many countries view illegal immigration as serious a problem. Common strategies to prevent aliens from entering the country illegally include building large barriers at borders, monitoring all tourists, and threatening serious punitive measures. In some extreme cases, corporal punishment may be involved. Often, countries do not consider long-term residence or productive input to society enough to negate the way in which a person got to the country. Sometimes, even adults who were born in the country to illegal immigrant parents can be deported.
Illegal aliens are often portrayed as a concern of wealthy nations, but in truth, every country has some illegal residents. Mexico, for example, is often portrayed as a source of many illegal aliens, but Mexico itself has illegal aliens from other countries. This issue is complex and global, because many people value freedom of movement and empathize with a desire for prosperity, while it is equally understandable to wish to maintain one's country. In the end, it is considered the nation's prerogative to decide who it will allow to live within its borders and why. On this issue, the morals and laws of the country appear to prevail.