Ronil Hira, an Indian-origin professor at US' Howard University, sparked a debate after claiming firms hire H-1B workers as they're controllable. "[H-1B workers] can both be legally paid less than American workers and...they're controllable, they're indentured to the employer. So it's a no-brainer for employers," Hira said. "I used to respect you," a user said. "Legalised slavery," said another.