> Phone numbers and ZIP codes can also be (and often are) used as proxies for race. Should HUD go after the phone companies and the postal service too?

I love the arguments that amount to: "if we can't stop <bad thing> everywhere, we shouldn't bother stopping it here either". I'm not sure how one expects any kind of social progress to happen with that attitude.

> Is it, in this case? Ad targeting has a zillion legitimate use cases, including some that are outright humanitarian.

Let's be real. The kind of ad targeting that happens on the internet is something quite different than demographic targeting by sending flyers to certain zip codes or putting ads in certain magazines. Because the process is largely a black box and the ads are only visible to those being targeted it's nearly impossible to audit by watchdog groups or go after the parties who placed the ads. In the realm of commerce this leads to a lot of borderline scams targeting the ignorant. In politics, this leads to radicalization and weird conspiracy theories like QAnon.

At best, modern targeted ads are a way to convince people they need something they do not. Something that "classic" advertising did as well. At worst, it's a channel for misinformation, scams, and sometimes malware. Completely invisible to you and me because we're not the "target demographic".