As an aside, I’ve seen this happen elsewhere as well. Classic play for wage theft. When I was working as a bartender in London to make ends meet, I had a coworker from Mexico on an expired visa. Great guy and the most hardworking. Well won’t you guess it, guy got picked up by immigration authority on payday.
Legal immigrants can claim benefits depending on their immigration status and whether they’ve been granted recourse to public funds; but the majority work their backsides off.