The gist is these companies are using algo/high frequency...

The gist is these companies are using algo/high frequency trading to artificially manipulate price to their benefit. They are also publishing dubious reports and twisting data in them for their benefit.

Short selling is legal and part of a functioning market. Manipulation is not ( but it happens) and reporting a narrative by twisting facts to your benefit ranges from a grey area to illegal but you will find rarely is any action taken.

Those are good questions to ask, but honestly i really think this is something to go and look at somewhere else if you don't want a range of biased opinions which range from factual to fanciful that you will get from many hot copper forums. Others will definitely disagree with what i have posted also.

Look up what is short selling on the likes of Investopedia and YouTube if you reading is not your preferred media.

That should give you a decent understanding.

Hopefully that helps