The U.S. Supreme Court today handed business a huge victory by making it more difficult for investors to file fraud lawsuits.

By an 8-to-1 vote, the justices ruled that plaintifs must show that executives knew they were engaged in wrongdoing. This will give companies another way win early dismissal of these suits without paying huge legal fees.

Though I hate crooked CEOs as much as the next person, I think the court made the right decision. Investors shouldn't be able to run to the court house every time a company's stock unexpectedly falls. Fear of these lawsuits has caused some companies to communicate as little as possible with investors.

The people who made out biggest in these cases were the law firms such as the class action kings at Milberg Weiss & Bershad, which was indicted last year, along with some of its attorneys, for allegedly paying kickbacks to clients involved in some cases.

Last month, The Wall Street Journal (subscription required) reported that the firm's David Bershad was in talks that may lead to a guilty plea to the charges. Another former partner, Steven Schulman, was indicted along with Bershad. Melvyn Weiss, the head of the firm, and former partner William Lerach have also been investigated by prosecutors though formal charges haven't been filed against either of them.

Ben Stein, one of my favorite financial writers, took a look at the issue of liability for investment frauds in his latest piece for the New York Times. In 1994, the Supreme Court inexplicably ruled that investment banks, accounting firms, and similar institutions could not be held liable for aiding and abetting securities fraud. Sound stupid? It is.

Fast forward to Enron. Last month, a three-judge panel in New Orleans ruled that a class-action lawsuit against investment banks involved with the company could not proceed. According to Stein, "The panel held that although its ruling might prevent justice from being done and satisfaction from being had, the acts of the investment bankers were at most aiding and abetting, not direct acts, and therefore not actionable under 10(b) as construed in the Central Bank case."

The case is now destined for the Supreme Court, and Ben Stein and I hope that they will do the right thing and hold banks accountable for participating in schemes that dupe investors. Given that most companies are insolvent after their collapses due to fraud, the banks and accountants are pretty much investors' only hope of getting some money back.

Patents have become a high-stakes game for tech companies. Of course, a glaring case is Research in Motion (RIMM), which recently had to shell out $612 million in a patent infringement case. The plaintiff in the case had no actual business; rather, its mission is to enforce its patent portfolio.

So, today's Supreme Court decision in favor of eBay is heartening news for the tech industry. The auction giant is the subject of a patent dispute with MercExchange over its "buy it now" feature. A federal court ruled in favor of MercExchange's injunction.

But this did not pass muster with the Supreme Court. Apparently, the High Court thinks injunctive powers can provide too much leverage on the part of a plaintiff; that is, it may force a settlement -- even if the defendant has a solid case.

In fact, in the eBay case, an injunction would have closed about a third of the company's business. Thus, the Supreme Court is not hiding behind fancy legal theories – but doing what it is supposed to do:  set policies on a national level that meet the broad requirements of the constitution.

Patent trolls are way more scary to U.S. businesses than the kind of trolls you find on message boards, or under bridges. So scary, in fact, that eBay is going all the way to the Supreme Court to argue against their ability to gain injunctions to shut down the businesses of the companies from whom they seek to receive damages.

In this case, eBay has been sued by tiny MercExchange over its Buy-It-Now technology (which eBay says has been altered to avoid infringement, anyway). A jury at the lower court found that eBay was infringing on MercExchange's patent, and then an appeals court upheld the finding, and imposed an injunction barring eBay from using the patented technology.

eBay hopes to make it harder for patent-holders to obtain injunctions (they're "virtually automatic" and can seriously harm a company's livelihood), and to have the court weigh a variety of factors before shutting down a business, for instance, whether or not the patent-holder plans to use its IP for anything other than lawsuits.