is that ridiculous disclaimer plastered over too many clueless websites:
All images on <website name here> are readily available in various places on the Internet and believed to be in public domain
This is crap, guys. Now, if you believe that everything online should be in the public domain, that’s an entirely different matter. We may even discuss it some other time.
But stuff readily available online is NOT by default in the public domain. Not at all. It never was. Get real. If, in 2013, you still put a “disclaimer” like that on your website, you are either lying or your “understanding” of copyright is screwed beyond repair and should be reset. Please do it. The current copyright system is a mess, but one of the first steps to reform it is to understand how it actually works.