Pretty sure it would just be lying since you know, no financial gain. Except it isn't even full lying since I did tell the truth about the company. I admit I might have gone a bit over the top when they announced that they bought another company and I tracked down every employee of that company to write them an email detailing exactly how they would be gutted with references to other companies that had been bought up and suffered the same fate by the same new parent company. Then of course found out they still had a fax number and sent them a fax. Had to make sure IT didn't try to hide it.
Maybe don't buy a small engineering/manufacturing company, outsource it all to China, and and all the while slash R&D + personal and you won't have people over a decade later still bashing you on Glassdoor.