Campaigns will still be able to target ads on Google based on users’ age, gender, location and the content of websites users have visited. But now they cannot direct their ads using several specific audience attributes, like political affiliation or public voting records. Campaigns will no longer be able to microtarget — tailoring ads to people’s specific data and behavior — which is the online equivalent of whispering millions of different messages into zillions of different ears for maximum effect and with minimum scrutiny.

And political organizations will no longer be able to reach “affinity audiences,” groups of users who are bundled according to similar habits. Google also clarified its rules around lack of truth advertising, banning ads with “demonstrably false claims that could significantly undermine participation or trust” in elections. And more: Campaigns cannot use specific names they have collected to target ads, and Google also disallowed “remarketing” to those who visit campaign web sites.

Twitter’s recent decision to get out of the political ad business altogether set this in motion. But Twitter’s move was mostly symbolic: Its political advertising business is small and not particularly critical for candidates, since they can continue to tweet to their heart’s delight.

Google — the search giant that also owns YouTube — is another story. Google and Facebook are the only two Big Tech players that matter in digital advertising, given the vast amounts of data they have sucked up on every aspect of the digital lives of billions of users.

In its public statements, Google sought to tie itself closely to old media, which has a lot of experience with political advertising. “This will align our approach to election ads with long-established practices in media such as TV, radio and print, and result in election ads being more widely seen and available for public discussion,” wrote a vice president for Google’s ads, Scott Spencer, sounding as if he were older and wiser than tech has been.