Well I can say where I was, most of the IT was H1B or offshore.
In SoCal it always seemed like there were a lot of them, too. But the news keeps saying there are only 80,000 H1B visas issued each year, so maybe they are just more concentrated in areas we worked and other parts of the country have very few. Or maybe they don’t expire and that 80,000 builds up year after year ?
At any rate, money talks. Make the visa fee $100K per year for each of them and companies will have to be truly desperate to utilize H1B visas. Then put a tracking anklet on them a month before their visa expires so they don’t disappear into the woodwork.