If it was gone that fast, the poster himself/herself may have had 2nd thoughts about posting it.

I can assure you that on my 2 main sites, we post articles all the time from where ever we find them, and there are no issues with it.

A publically acquired document is fair game, unless there is a clause that it cannot be reproduced etc etc...

I am careful not to post certain items that may be in conflict with Agora as a competitor, but that's out of courtesy more than anything else.