Good for them - long overdue.

They would have probable cause to detain every person in the facility. The only thing long overdue is the action finally being taken to weed out those stealing jobs and community resources from Americans and putting peoples lives at risk in the process.

What probable cause?

Their ethnicity?

So, is "working while Hispanic" the new "driving while black"?

Exactly. Far from probable cause, all they've got is racial profiling. Yet another way law comes down harder on non-white Americans than on white ones.

Not probable cause for the raid. The raid is not the issue. The detainment is the issue and unless you have facts that are not in the story, then probable cause seems like a justifiable defense for the detainment of those found without ID or some worker permit. In the execution of a legal raid, there is no such thing as illegal detention during the raid.