A bug has accidentally given some Google Ads users access to ICS, an internal tool meant for the Google Ads support team and it is not intended for public use.
Many PPCers have shared on social media, with Geert Groot being one of the first, that they can see it, suggesting this likely isn’t limited to just a small group of accounts this time.
The Audience builder is the only option available under Internal tools, but leads to an empty page.