I believe most of those are patents filed by US graduate/PhD students of foreign origin working for big corporations either via H1b or using their student visas

I believe most of those are patents filed by US graduate/PhD students of foreign origin working for big corporations either via H1b or using their student visas. These are the individuals we want to keep. The "dark side" of H1b program is various ethnic sweatshops often filled with mediocre talent unable to find work anywhere else. I have known a person in Boston area who, along with 4 roommates, lived in his "owners" (H1b sponsor) basement where they were looking for contracts for themselves, so the sponsor could sell them later for a percentage. This crowd doesn't file patents. Another, less evil "H1b business" is what many 3rd grade no-name universities do: they bring people from all over the world using student visas, give them loans, put them through 6-8 month Java crash-course, after which students are supposed to find themselves H1b employment. When they do, they have to pay $10-30K to their "school" while completing their "education" online (the requirement that lets these institutions maintain their legal university status). I suspect that these shady H1b sponsors take up as much as half of all H1b visas issued to programmers year after year. As I said, big companies rarely bring people from overseas, they like to hire the best foreign graduates from good schools instead, where H1b works as a temporary bridge between a student visa and a green card, and that was the original idea behind it, IIRC.