> making targeted advertising illegal

how do you define targeted though? General definition would make almost all of the political ads illegal.

I think the resolution matters, as this article mentions.

Putting an ad on a bench of a district where 70% of the >100K residents belong to a certain interest group is targeted, but in a way that is obvious to anyone and fair.

Sending online or mailed ads to people who belong to the intersection of three or more groups, as identified by signals that are difficult to observe (shopping habits, search history, social media interactions) is a line I think most consider wrong to cross.

You could prohibit targeted advertising based on membership in a "protected class"[1] (race, religion, sex, etc.) - I think one of the problems with targeted political advertising on social media is that a lot of it seems created for the purpose sowing conflict between these groups. I struggle to come up with a legitimate reason a candidate would ever need to tailor their messaging based on those groups.

[1] https://en.wikipedia.org/wiki/Protected_group

The targeting can easily be neighbourhood, so you can say neighbourhood 1 (that likes Pizza) gets messaging that says candidate A loves pizza and everyone should get a free one, and also tells that neighbourhood that candidate B hates pizza. Then in another Neighbourhood that hates pizza they advertise the opposite.

You can get a reasonable approximation of that targeting in real life as well, but it is harder to hide that that is what you’re doing. Whereas with online targeting you are never aware that the other ads exist.