That's an unfair comparison. A three line snippet is hardly the same thing as taking an entire page. Not to mention that all search engines do this.

There is at least an opt out to Google, there is some benefit to showing up on Google search, and there is a significant transformative action both in aggregating and summarizing, and in providing web-pages based on a keyword search.

That said, there is an argument to be made here. One that's included in the disputed EU copyright directive in the 'link tax'.