Depend on which area of Immigration Custom you are referring to, it can be separating families, documentation problem, ICE (Immigration Custom Enforcer), places a detainer on the individual, and etc. But the main purpose is principally responsible for immigration and customs enforcement, with additional responsibilities in countering transnational crime. Easy say the Immigration Custom are trying to keep thing that are not suppose or cause problem away from entering and/or exiting this country or the country they are enforcing in. I did spend some time working for Immigration Custom so it is really depends on what area you are working and what is your responsible duties are, it can be easy and smooth or hectic and stressful. Everyday the Immigration Custom has problem just depend it is big or small.