Most people who are living illegally in the United States do so with little or no fear of deportation. This is because with the high number of illegal immigrants living in the United States it is not uncommon for most people to get by their whole life without having to be subject to deportation.
However, as a law firm handling immigration in Nevada we see that for every person that lives their whole life without getting picked up by the Department of Homeland Security their is that person who gets pulled over for speeding and is sent to jail on an immigration hold. As a lawyer I can tell you that this is a complete nightmare for the average person. Usually the person getting caught on a traffic stop who is hauled off to immigration for deportation is a model US Citizen. They probably have a family here in the states, a good job, and even pay their taxes (albeit on a borrowed social securty number). Their one problem is that when they came to the United States, barely able to speak English, they did not know how to properly go through obtaining a visa or green card in order to make sure that their stay here was legitimate.
Here is typically what happens if you or a loved one is caught on an immigration hold by the authorities. If you were somehow caught, they will take you for processing and hold you until immigration comes to pick you up. Once immigration comes to pick you up it typically takes a day or two for them to process you (depending on how back-logged they are). After a day or two a loved one can come and post a bond to have the detainee released. Typically, this should not be a problem as long as the detainee has no criminal background or looks like a flight risk.
Once the detainee is freed on bond, that detainee will receive a court date to go in front of an immigration judge for the beginning of the Removal Proceedings. At this time, it is always good to have a competent lawyer who can navigate the legal system on your behalf. However, at the end of the day, there is only a few ways that one can be saved from deportation. To become legal in the United States after having been out of status and/or illegal, there is only one way: through marriage to a US Citizen.
This is why the process is so strict, ending in an interview with the couple and an Immigration Officer to ensure that they have entered into a "Good Faith" Marriage. Therefore, this is the only way you can be saved from Deportation... a good faith marriage to a US Citizen. Otherwise, your other options are either not as good or will end up in Voluntary Departure.