@Pwnallthethings also people waiting for employer sponsored green cards. this process takes years and makes the functional slaves. My former roommate in US (a programmer) was working for a small company who sponsored his green card application. They had constant and large staff turnover but he couldn't leave (and was paid very little). By the time I lost touch with him he's been waiting for 4 years. I assume he got his green card eventually but I don't know how long it took in the end.