recycling-bin diving?

Cardo just brought home a big trash can so we can start composting. (Right now, we've been saving our foodstuffs in a bag hanging from the grill on the back patio.) We're completely new at this, so we'll see how it goes. I've been reading enough about it lately that I just can't not give it a try.

So, we were out for a walk today and the area we were in is having their garbage and recycling picked up tomorrow. Many had already set out their trash cans and recycling bins. In front of a couple of houses we passed, piles of black garbage bags were lined up. I'm guessing these were full of lawn clippings, but I wasn't adventurous enough to peek. In front of a couple of more houses were recycling bins full of newspapers and paper bags. I really wanted those newspapers, or brown waste (I'm trying to learn the jargon). I didn't take them.

What I am wondering: Is it okay to take stuff from someone's recycling? The person who put it there obviously didn't have any further need for it. Should I go knock on the door and ask? What do you think?