If and when the author (including me, I routinely do that on OTHER websites I run, or contribute to!) of some web page, video etc.. tells you that you can copy it all elsewhere, by all means DO it. In all other cases, including “sharing” them on Facebook or similar networks, or sending the full thing via email, you do a serious disservice… not just to that author but, **above all, **to all the people with which you “share” that stuff.
Why? Because, by definition, if they can see what you copied they could have seen it just as well** MUCH BETTER** on the original website. Because that is the ONLY place where everybody could immediately :
be sure that they are reading the last version of that piece, with all corrections, updates and so on
see who the author is, what else she does and, if they want it of course, how to support her
read other pieces from him or her, if they like what they read
criticize or discuss that content directly with the author herself, and everybody else who already did the same
by “copying online stuff without authorization, you deprive_ all other Internet users of all these possibilities. Why? Is that right?”_
This is the reason why the Copyright Policy on this and my other personal websites says what it says.