Washington, DC (CNN Business) YouTube has prevented President Donald Trump from running a number of ads on its platform this election season, its CEO acknowledged on Sunday. But the exact reasons for the decisions are unclear, once again raising questions about the policies of YouTube and its parent company Google.

In a report on Sunday, CBS's "60 Minutes" said it found more than 300 Trump campaign ads have been taken down from YouTube and Google this year. In an interview, YouTube CEO Susan Wojcicki told CBS that more information about the ads can be found on Google's ad transparency website.

But Wojcicki's response underscores how little information Google provides to users about ads that have been removed. Ads that have been taken down, for example, cannot be viewed in the ad transparency tool due to what Google's website says are "technical limitations." Users can only see that a particular ad has been blocked — not its content.

Google also does not disclose specifics about why an ad may have been taken down. In the transparency tool, blocked ads are covered up by a message explaining that the ads have violated Google's advertising policies, and links to a page outlining what Google allows and disallows on its platforms. But Google's tool does not explain what specific policy an offending ad has violated.

The inability to view an ad that has been taken down, and the lack of clarity surrounding Google's reasoning for a removal, could make it more difficult to hold both the company and political campaigns to account.

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