So far. ;)

We pay for 'em, so they're our property, to be quoted in their entirety if we are sadistic enough.

There's been some controversy recently over whether unreleased or "draft" documents are public property. This has more to do with technology and storage than with any nefarious plots by any political party. We don't have carbons anymore; electronically stored documents are routinely written over and so destroyed and replaced. The argument concerns whether that gives precedent to the idea that any ephemeral document, even if it still exists in its intact form, is public property or if it only becomes public property when it's released to the public. I tend to think that all govdocs are public property because we pay for all aspects of their production. The issue can potentially affect investigations into and research on government actions, because if only released govdocs are public property, to whom do the unreleased documents belong? Their authors? Their authors' departments? We the people? If there's been an official ruling on this, I haven't heard about it.

When quoting from a subscription service source, you have not only the author and the publisher, but also the subscription service to contend with. None of them want to lose income, and if we, the public, reproduce and give away work for free, no income. That would be the primary -- maybe even the only -- motive for the publishers and the subscription services to defend copyright.

Authors often have other, more complicated motives. Sure, it's the money, but it may also be that certain uses of the work are repugnant to the artist, who wants right of refusal.

There are things I read that I would love to share with people, but I know I can't, and in my case, I really really can't. The "oops" moment doesn't work as well for someone who has copyright law posted all over the place at work. :)