There are separate requirements for Mexican visitors. Citizens and permanent residents of Mexico generally must have a nonimmigrant visa or Border Crossing Card (also known as a "Laser Visa"). Applicants must demonstrate that they have ties to Mexico that would compel them to return after a temporary stay in the United States. U.S. consular officers look for evidence of strong family, business, or social ties.

All nonimmigrant Visas application fee is $100.00, e.i. just for the interview. If the applicant is rejected, the $100 fee is not refunded.

For the immigration visas the process is much more difficult and expensive: according to wikipedia "after all processing fees have been paid, most immigration visa applicants pay well over $1,000 to become permanent residents in the United States and are forced to wait several years before actually immigrating to the U.S."

There are eighteen different categories of nonimmigrant visas. The number of visas for most of these categories are not limited, but just some categories allow their holders work in the US.

Immigrant visas allow aliens to stay in the US permanently and work. However, Congress limits the number of immigrant visas. 

 [10] 

 The US Patriot act:

This legislation significantly enhanced the law enforcement, surveillance, and detention powers of the government with respect to noncitizens. It is an act which president Bush signed into law on October 26, 2001. It dramatically expanded the authority of U.S. law enforcement agencies for the stated purpose of fighting terrorism in the United States and abroad. criticized becaused considered to go against civil liberties. It contemplates the authorization of indefinite detentions of immigrants.

- increased survelliance procedures,

- more border protection,

- increased the authority of the INS to track down illegal immigrants with ties to terrorism.

Essentially what the P A has done is make it more difficult for non-citizens to gain U.S. permanent residency, citizenship, visas and work permits.  if there are any doubts regarding an applicant then they do not receive approval.

ILLEGAL IMMIGRATION AND PROBLEMS RELATED TO IT:

CAUSES

METHODS

DATA

IMPACT ON THE SOCIETY

ILLEGAL IMMIGRATION:

Illegal immigration means migration across national borders causing violation of the immigration laws of the destination country. On contrary, illegal emigration refers to the process of leaving a country in a manner that violates the laws of the country being left.

CAUSES:

People move from one country to another for various reasons. Hereafter, I present most frequent reasons why people leave their own homes:

1) WAR AND REPRESSION 

One driver of illegal immigration is an attempt to escape civil war or repression in their native country.

After 6 years of armed conflict, roughly one of every 20 Colombians now live abroad. Figures from the US Department of Homeland Security indicate that Colombia is the fourth-leading source country of unauthorized immigration to the United States; The estimated number of unauthorized Colombian residents in the US has almost tripled from 51,000 in 1990 to 141,000 in 2000.

Numerous refugees came to Italy during and after the war in Ex-Jugoslavia and Albania. While refugees from East Europe and Ex-Jugoslavia reached Italy crossing its borders through north-oriental regions, people from Albania reached Italy across the Adriatic sea.

2) NATURAL DISEASES

Other reason why people move from one country to another is because of natural disasters, such as tsunami, alluviums, of earthquakes.

3) ECONOMICAL REASONS: POVERTY

Another reason for immigration is to escape poverty. The poverty is often caused by war situations or natural diseases. But sometimes the person moves over the border because the wage-labour ratio is much higher in the neighbouring country, as is the case with the US illegal immigration.

4) PERSONAL REASONS:

The causes I listed before are in some way situations decided by politicians or by nature and people in that cases are just passive observers, they can only endure. But there are other reasons, more personal, as those listed hereafter:  

- FAMILY REUNION

Some illegal immigrants seek to live with loved ones, such as a spouse or other family members. So they look for documents their family need to reach them.

- ACHIEVEMENT OF THE PENSION  

As one achieves his/her pension, he can decide to move to another country because in that place the climate is better and because living costs are lower.

-CRIMINAL REASONS:  

One can leave his/her own country in order to escape the justice or his fatherland or to avoid being arrested.  

5) PROSTITUTION AND SLAVERY:

The so-called "white slave trade" referred to the smuggling of women, almost always under duress or fraud, for the purposes of forced prostitution. Now more generically called "sexual slavery" it continues to be a problem, particularly in Eastern Europe and the Middle East, though there have been increasing cases in the U.S. People may also be kidnapped or tricked into slavery to work as labourers, for example in factories.

METHODS:

1) BORDER-CROSSING

There are different ways in which people can enter in a country in illegal ways. In America, immigrants from nations that do not have an automatic visa agreements, or who would not otherwise qualify for a visa, often cross the borders illegally in some areas like the U.S.-Mexico border, the Strait of Gibraltar, Fuerteventura and the Strait of Otranto. These methods are usually very dangerous. It often happened that many immigrants suffocate in shipping containers, boxcars, and trucks, sink in vessels, die of dehydration or exposure during long walks without water.

Smugglers, known in the US as "coyotes", often charge a hefty fee, and have been known to abuse or even kill their customers in attempts to have the debt repaid. Sometimes immigrants are abandoned by their human traffickers if there are difficulties, often dying in the process. Others may be victims of intentional killing.

In Italy, many immigrants follow illegal way to enter the country, so they usually get in contact with people who are known as real neo-slavers, managing human traffics. An example is that of so-called ‘scafisti’ of the Mediterranean Sea, who wring together huge quantities of people into unsafe and old boats (le carrette del mare) departing from African coasts and arriving into Mediterranean countries: Italia is one of the favourite destinations because the journey from Africa to Sicily and in particular to Lampesua is shorter than to other possible destinations. For many of them the journey continues to other europena countries. These ‘scafisti’ received huge amounts of money for a hope in new life, and very often they are in contact with different criminal organizations and sometimes with the police. In this ‘viaggi della speranza’ many people lost their lives, also children and pregnant women.

2) OVERSTAYS

Some illegal immigrants enter a country legally and then overstay or violate their visa. For example, most of the estimated 200,000 illegal immigrants in Canada are refugee claimants whose refugee applications were rejected but who have not yet been ejected from the country.

A related way of becoming an illegal immigrant is through bureaucratic means. For example, a person can be allowed to remain in a country - or be protected from expulsion - because he/she needs special treatment for a medical condition, etc., without being able to regularize his/her situation and obtain a work and/or residency permit, let alone naturalization. Hence, categories of people being neither illegal immigrants nor legal citizens are created, living in a judicial "no man's land".

A visa overstayer is someone who has entered the United States with authorization from the Government and then illegally overstayed his or her visa. Or they have entered US using a Border Crossing Card (BCC)^[10] and then violated the restrictions imposed upon card holders. Visa overstayers tend to be somewhat more educated and better off financially than those who crossed the border illegally.^[11]

To help track visa overstayers the new US-VISIT program collects and retains biographic, travel, and biometric information, such as photographs and fingerprints, of foreign nationals seeking entry into the United States. It also requires electronic readable passports containing this information. According to Secretary Michael Chertoff,[14] the single biggest handicap to this system is its lacks of facilities to routinely monitor and document who goes over the land borders into Canada and Mexico from the United States.^{[citation needed]}

The Pew Hispanic Center calculated that 1.9% of all nonimmigrant arrivals between 1998 and 2004 resulted in overstays, with a proportion varying widely by country of origin. The calculated share of Mexican legal visitors who overstay is lower (1.7%) than for Central American (3.2%) or South American (2.4%) nationalities, which the center explained was " because it [is] easier for Mexicans to make illegal entries and harder for them to get visitor visas." [15] A 1995 U.S. General Accounting Office (GAO) report gives estimates for all countries based on data from 1990-91 showing that Haiti, China, India, Korea, and the Philippines (plus others) had overstay violation rates as high as 8% or higher.^{[citation needed][12]} In general the poorer the country they came from the more likely the foreign visitor was to violate their visa.

 Terms of entry

Another way people become illegal immigrants is by violating the terms of their legal entry; for example, tourists may become illegal immigrants by taking jobs in the United States.[16] Technically speaking, however, such a person, although out of status, does not become an illegal immigrant until either the expiration of the term of their original legal entry or formally ruled by DHS to have violated their status, whichever comes first. The act of accepting unauthorized employment may be unlawful, and subject the former tourist to deportation, but their presence in the country does not itself become unlawful until either a formal ruling to that effect is made, or the original term of admission expires. Thus, a tourist who accepts unauthorized employment, but who voluntarily leaves the USA before the original term of admission expires and before legal proceedings are initiated, may reapply to enter the USA without triggering any of the statutory bars that ordinarily apply to illegal immigrants. Readmission, however, may be denied at the discretion of consular or border officials if it is felt the person is likely to again violate their status in the USA.

One common means of violating status (terms of entry) was coming to the U.S. on a student visa and not going to school or not leaving the country after finishing school.^{[citation needed]} Technically speaking, this was a status violation, not an overstay, because foreign students were typically admitted for "duration of status" rather than until a fixed expiration date. The lack of a fixed expiration date coupled with a lack of knowledge of the changing academic status of purported foreign students meant that it was very difficult for U.S. Immigration and Customs Enforcement to track status violations by foreign students. The number of foreign students in the United States is over 600,000. However, this practice has been somewhat curtailed with the introduction of SEVIS, whereby the universities electronically report any no-shows and irregularities to U.S. Immigration and Customs Enforcement. The lack of follow-up by a severely under-manned ICE [17] severely hampers the effectiveness of these reports.^{[citation needed]}

Another form of illegal entrance into the United States (mostly from Northern Mexico) is where often very young, pregnant girls come into the United States to give birth to children who are, by U.S. Law, legal citizens and the girls gain status to raise their American-born children in the U.S.

IMPACT ON THE SOCIETY:

Some economists have argued that whether the impact on the U.S. economy has been good or bad depends on which section of the U.S. population one is most concerned about. The cost of labour has cheapened and this has benefited business owners, but had a negative effects on some American labourers in certain unskilled fields.

A growing issue is gangs which are made of and support illegal aliens such as Mara Salvatrucha. According to a Maldon Institute report, MS 13 “appears to be in control of much of the Mexican border and, in addition to its smuggling and contraband rackets, the gang collects money from illegal immigrants that it helps [move] across the border into the United States.” Its members have committed murder, severed limbs, assaulted, robbed, and raped and are protected by international law with El Salvador. "The Salvadoran gang, known to law enforcement authorities as MS-13 because many members identify themselves with tattoos of the number 13, is thought to have established a major smuggling center in Matamoros, Mexico, just south of Brownsville, Texas, from where it has arranged to bring illegal aliens from countries other than Mexico into the United States."^[

"A growing number believe that immigrants are a burden to the country, taking jobs and housing and creating strains on the healthcare system," the Pew Hispanic Center wrote recently. "Many people also worry about the cultural impact of the expanding number of newcomers in the US."

As many immigrants entered in Italy illegally, they cannot find work in the official job market. Therefore, they are usually exploited by their employers whose used the low cost labours. For this reason immigrants are accused of lowing the average salary (the phenomenon of ‘svalutazione sociale’) and of stealing job to native citizen. Many of them end into criminal organizations, which take advantage of them to do the so called ‘lavoro sporco’ (dirty jobs)

These two aspects, ‘svalutazione sociale’ and criminality, increase problems of ghettoization and xenophobia, decreasing the possibility of a good integration into the host country.

SOME DATA ON AMERICAN ILLEGAL IMMIGRATION:

The Pew Hispanic Center state that 57% of illegal immigrants are of Mexican origin and about 75% are of Latin American origin. They also report that while the number of legal immigrants (including LPRs, refugees, and asylees) arriving has not varied substantially since the 1980s, the number of illegal imimgrants has increased dramatically and, since the mid 1990s, has surpassed the number of legal immigrants.

The Pew Hispanic Center, a nonpartisan research organization in Washington, estimates 11.5 million to 12 million "unauthorized migrants" live in the US today

SOME DATA ON ITALIAN ILLEGAL IMMIGRATION:

Illegal immigrants reaching Italy are especially people from Africa – desperation, lack of future expectations, social anarchy – from Asia – essential because of the demographic pressure of its inhabitants and economical conditions – from war sceneries (those from Balkans are deceasing).

CITIZEN'S REACTIONS

REFUSAL: RACISM

ACCEPTATION: ASSIMILATION, INTEGRATION