This is reminiscent of how Facebook used to allow people to microtarget job and housing ads to people based on protected classes like race, age, and gender. Th

This is reminiscent of how Facebook used to allow people to microtarget job and housing ads to people based on protected classes like race, age, and gender. They ended up reaching a settlement and being forced to change their filter criteria due to civil rights laws. So I wouldn't be so sure that "merely providing the tool" is necessarily an entirely legal action.