Be careful with your logic and framing. I explained why it was poor framing above. But the way you've (and the gp) framed it is dangerous. Swap "voip numbers" for "x skin color" and you're in clear unethical and illegal territory. But swap the attributes of the parent and you don't get this issue. If parent is x race and all their friends are also x race you're not discriminating against y race through their means because they aren't turning down based on race, it is just closer to changing the odds. The problem isn't when you change the odds (unless there's an extreme manipulation) but rather how you respond to samples from the distribution.