Tangentially, so could Google.
Baseless accusations like that will get you nowhere.
Wasn't the issue that the app displayed the YouTube videos without the advertisements though, and this was against the Terms of Service?
Google would be remiss if it wasn't trading against the massive wealth of data it has. They're probably not mining email (though they could use a proxy and look at the frequency of particular ads' being displayed in Gmail), and probably have a privacy line, somewhere, that they're unwilling to cross. But I'd be surprised if most people ended up being comfortable with that line's placement. And it's not like we have any way of knowing where it is.