http://en.wikipedia.org/wiki/Citizenship_and_Entry_into_Isra... - prevents residents of Iran, Afghanistan, Lebanon, Libya, Sudan, Syria, Iraq, Pakistan, Yemen and areas governed by the Palestinian Authority from automatically gaining residency and citizenship through family reunion and marriage.
http://en.wikipedia.org/wiki/Law_of_Return - Allows almost any Jew or relative of a Jew to migrate to Israel and quickly gain citizenship.
http://en.wikipedia.org/wiki/Citizenship_and_Entry_into_Isra... - prevents residents of Iran, Afghanistan, Lebanon, Libya, Sudan, Syria, Iraq, Pakistan, Yemen and areas governed by the Palestinian Authority from automatically gaining residency and citizenship through family reunion and marriage.