Google is aware of what they are doing
When Google increased the video length of youtube they did so with the intent of a bigger strategy in mind. They realized that people would start uploading pirated videos to their service. Google sat and watched this develop and thousands upon thousands of full lengths films were uploaded. Google added functionality such as play lists and other features to make it much easier for people to find this pirated content.
Of course now Google wants to monetize all of the pirated content on their service. They started getting more aggressive with the ads and introduced their "Youtube red" service to make the ads go away.
Google is fully aware they are providing pirated content but their excuse is "we did not upload these". While they did not upload the content they are providing the framework and the incentive for people to do this. Google pays these pirates a cut of the ad revenue.
If the copyright owners want to be paid for their pirated works perhaps they should go after Google. The copyright violaters themselves are getting the smallest part of the cut from the revenue. Google is making most of the money from this illegal content. Only in America can someone steal content upload it to the internet and have a major corporation that should know better profit from it.