"What that bill does is further emphasize the right in California of students to claim their own gender identity to use the facilities of their choice, restrooms and locker rooms," Tyler tells OneNewsNow.
The legislation passed in the California Assembly in May without any votes from Republican lawmakers, the Los Angeles Times reported.
Much like Tyler's warning, the newspaper also reported the law would allow transgendered students "to participate on sports teams and use bathrooms that correspond with their gender identity, not their sex."
Tyler says the legal group has spoken to numerous girls in public schools who say they feel vulnerable with males who claim to be females. These males are currently allowed to use the girls' locker room. AB 1266 would take that to the next step.
"For example," Tyler says, "a boy could choose to be on the girls' swimming team or a boy could choose to be on the girls' basketball team based upon his own identity that he has established for himself or claims to identify with."
The spokesman for Advocates says the legal group is defending the rights of students who do not want to participate in the state's trend of "gender liberation."