Commonly known as "shorting" I assume ?
Planted articles, algoritm and robots...
Shorting is not market manipulation.
There seems to be some quite a few misconceptions about shorting. First of all every transactions has a long and a short side. When I buy Apple stock I am long Apple and short GBP, how if I have used any margin of margin on this transaction (i.e. borrowing), I have borrowed GBP to to sell it for Apple stock. Which, conceptually, is no different the borrowing Apple stock to sell for GBP.
Sure shorting can be used for market manipulation, but so can going long.
Shorting is use for many purposes, reducing market exposure, delta-hedging, expressing a bearish view, etc . There are also other tools that allow for similar payoff structures such as put options or futures (short side).
GME has had high Short interest for most part of 2020, yet its price has been rising since July. If there was market manipulation there from hedge funds, then it was a very poor attempt. The point of shorting this stock is to benefit from a fall in price, not to push the price down yourself, since then you don't accrue the benefit of that reduction. Hedge funds primarily shorted this because they expected this company to be the next blockbuster. Shorting doesn't cause a company to go bankrupt, poor management does.
Shorting plays a vital part in reduction of asset bubbles (obviously does not prevent all), and bubbles are far more common in assets that are difficult or costly to short.