If they've overstayed their visa or their visa doesn't permit them to work, I'm confident they'll be sent back to wherever they came from.
I've traveled and worked in other countries. You have to carry your passport (or a certified copy of it) along with your visa everywhere in case you are stopped by law enforcement - otherwise, out you go.
This is normal stuff, people, and these workers should know that.
You have to carry passport everywhere only in police states like USA or Russia.
I've lived and worked in countries in South America and Africa and if, as a foreigner, you are stopped (which happened randomly on roads and in cities) and don't have your papers, you could be deported. It was recommended by the US State department to carry a certified copy of my passport and visa information.
The Trump administration has been in court several times already for trying to deport people who, not only are not supposed to be deported, but whose deportation would and is be illegal.
Even if they're released, ICE is known to be abusive and inhumane in it's detention practices.
Your response reeks of "they'll be proven to be illegals soon enough, and then all the abuse is fair game". Disgusting.