This video will grind your gears. It's actually old but if anything the problem has gotten worse.
Law firm teaches HR departments to get around hiring US workers so they can hire cheaper H1B visa workers.
https://www.youtube.com/watch?v=TEwJvmJj2uo (https://www.youtube.com/watch?v=TEwJvmJj2uo)
https://www.youtube.com/watch?v=Fx--jNQYNgA (https://www.youtube.com/watch?v=Fx--jNQYNgA)
The job boards are generally filled with "fake jobs" that are just resume reapers.
Staffing companies want to have a good picture of who they need to find a way of disqualifying. Knowing which US workers are available before posting real jobs so they can tailor the requirements to get around available US workers. They have computer programs that specifically report in real time whether there is a US citizen qualified for the job as they type the description. If there is.. backspace.. try over. etc etc...
And the foreign workers routinely lie about their qualifications.
These head hunters are worse than car salesmen, lawyers, scum sucking bottom feeding ass clowns.