The only time I used photos that weren't mine, was for my scrapping for other business... I needed examples for wedding and babies that wasn't just of mine. haha... however I did purchase the rights to those.
For general scrapping... it's your scrapbook and if you aren't going to publish the layout with the image on it, I'm okay with it... I personally wouldn't even put it in the gallery since with the explosion of pinterest, your not sure who will see/where that layout will end up...
That is why I'm a fan of the photoless layouts... haha