Pavel:  "Short or long alike. I would say that stock pumping is even bigger issue than shorting."

Bashing and shorting at the same time, especially "on the margin" shorting, is a combination conceived in hell and executed by some, not all, Hedge Funds.  It is often attempted by "retail investors" as well, although it is much more transparent when the source is a retail investor. The bashing and shorting concurrently is its own set of problems, but when you through icing on that cake consisting of margin financing you are creating the iceberg that sank the Titanic.

Just an opinion only, mine.