Initially, my thought was Roku too, since I see them as more aggressive with sharing/ selling data. I assumed Roku OS might have some ability to look into an app to see what it’s doing.
However, after reading the new Plex privacy policy I now believe it was Plex but it was more of an oversight with my account. I have a very old account so my understanding that any sharing I would have enabled according to their policy. I also made sure last year that nothing was being shared with the options available then. I also believe my IP was being used to associate this data with Google.
That said, the new options in my account were new to me and the options were unchecked. I just checked them today so I’ll have to see if YouTube gets wind of my watch history now. As long as it stops I’ll be happy about it.
