There are some reposts here from commercial news, such as AP and BBC.
This is done only with selected articles.
The topics are globally significant, and in some case it is urgent to distribute the information as much as possible- for reasons of health and safety and welfare.
Simply put, if the information is withheld, more people will die. The information will save additional lives if it is distributed further.
The agencies have a right of exploitation and in some cases they directly pay for the authoring of the articles. It is professional work which must be paid for. However, all these articles already have been exposed in the 10s of millions pageviews at the time of repost.
Without the repost, the articles would disappear and will become forgotten. Here they can be found again with the help of keywords!
The reposting is seen as application of the rights of fair use. The total view count is very low currently. All the copyright information is included. It will increase reputation of the agencies.
Ebooks from Allaboutcircuits.com
Their license permits republication explicitely. There is not a copyright disclaimer on all the pages, however the URLs all include AAC, and they are child pages from a page where such copyright information can be found.
As such, the copyright information is not difficult to find.