It's not limited to the Bay Area. They do the same thing in the Midwest for industries with high-turnover. They use the same, obviously dishonest tactics, like only advertising positions in the classified sections of local newspapers, where no one would ever look for them.

I'm fully in favor of immigration (mom is an immigrant and so is my partner), but the H1-B system was obviously designed to create a tier of second-class workers who fear losing their sponsorship and thus tolerate lower wages and worse treatment. These visas need to be fully portable at any time, offered for positions only at above market rates, with greencard queue times also being drastically reduced and made independent of employer sponsorship.