I am a engineering manager and was recently hiring to fill an open position. A former Cisco software engineer, with the skills needed, applied for the position and was interviewed by my team. One member of the team is a former wipro who worked at cisco in the past. That engineer reached out to h1b's at cisco, without consent, and based on what they heard strongly recommended against hiring the candidate.
Treat those h1b's and wipro things kindly or they may stab you in the back some day. The legality of the reference check doesn't matter to these ?people!