Is Google justified in using the search history of unaware customers to target them with ads? Take a stance and support your answers with actual examples.

Please review blog post: 

https://adexchanger.com/ad-exchange-news/first-google-lets-advertisers-use-search-data-youtube-ad-targeting/

Answer the following question:

Is Google justified in using the search history of unaware customers to target them with ads?  Take a stance and support your answers with actual examples. 

200 word minimum

Please include references