Back in 2005/2006, there were a number of raids focusing on meat packing plants in the midwest. The investigation started when a routine check of one Immigration employee turned out that she was working simultaneously (well, her name & SSN were) at more than 50 places (and the IRS wanted about $200k in unpaid income taxes). Much of identity theft is focused on the Hispanic names & SSN because those are the ones that companies hiring illegal immigrants need in order to get past the electronic verification systems.
If there were actual jail time for complicit managers, there would be no market for illegal immigrants.
0 - https://cis.org/Report/2006-Swift-Raids
1 - https://en.wikipedia.org/wiki/Swift_raids
The Denver Post used to have the articles online, but they've since been scrubbed.