Yes, Regulation SHO was enacted to address and regulate locating and delivering short sales and short positions. Just google the topic or check the SEC Site.
I don't have any links for it, but at some point I believe the SEC did establish that PIPE holders can't short against their restricted shares.
But what the judge is saying in that case is that it was determined that the shares shorted came out of the public float, not from the PIPE holders restricted stock, so there was no problem.
Market Data 
Markets 
AI
