IMO this is one of those things that is going to have to be looked at on a case by case basis.
And how are do you want to go with it, partly because the quoting feature of this forum is meh at best

If when you selected the text and clicked the quote button a box popped up asking where the quote was from and you had to put in a URL or whatever then it would be different.
For now *I* feel the quoting the text and putting in a line before it that says "A quick google search found this:" should be fine.

You are saying it's not your work, and for most things that is close enough.
I know it can be abused, which is why I started with the case by case basis statement.

-Dave