And, what countries are they coming from? While that can't be determined, we can look at who gets caught.

Based on the (uncorroborated) FY2003 information here, this is a breakdown by region of those who were caught trying to cross illegally from Mexico:

• <500 from Caribbean countries
• <100 from smaller former Soviet countries
• <500 from Europe (28 countries; 4 from Norway, 1 from Sweden)
• 125 from non-Arabic Africa (including 26 from Nigeria)
• 650 from Asia (including 286 from China)
• 190 from Arabic/Muslim/Middle Eastern countries (3 from Afghanistan, 40 from Pakistan, 2 from Saudi Arabia, 7 from Yemen)
• 10 from Australia
• 26 from Canada
• 4 from New Zealand
• over 900,000 from Latin America (95% of that number from Mexico)