Just the hint of an SEC investigation or civil lawsuit can send stocks into freefall. Some cases mean a death sentence for a corporation (see: Enron), and even low-level employees can face prison time.

“Greed is a growth industry, and always has been,” says Max W. Berger of Bernstein Litowitz Berger & Grossman. “For all the honest financial people in the world, there’s many dishonest people looking for shortcuts to acquire wealth. I’ve been prosecuting security-fraud cases for 43 years, and every time I think I’ve seen the worst of it, a few years later something worse comes along.”

Securities fraud and investment fraud encompasses a spectrum of wrongdoing from embezzlement to Ponzi schemes. One of its most basic forms involves corporate officers either willfully or recklessly giving investors faulty information that influences them to buy or sell shares.

“Many of the matters we’ve been handling the past few years arose out of the financial crisis we just lived through,” says Daniel J. Kramer of Paul, Weiss, Rifkind, Wharton & Garrison in New York. “These are challenging questions and complicated markets. It’s an exciting time.”

Technology makes it even more exciting.

“Emails have brought about convictions that you wouldn’t have even been charged with before,” says Robert S. Fink of Kostelanetz & Fink.

“I worked with an individual in a fraud case a few years ago, and the one document the government was relying on was a joke from one of his supervisors, who forwarded an e-mail about new regulations and a crackdown on violators,” says Barry H. Berke of Kramer Levin Naftalis & Frankel. “He said in the [subject line], ‘This means you!!!!!’—with five exclamation points—clearly intended as a joke. That is not a helpful email for clients.”

A century ago, the phrase “securities fraud” didn’t mean much. There was no major federal law governing the trade of securities, which were covered by a variety of state laws of varying degrees of laxness. It took the 1929 stock market crash and the New Deal for the Securities Act of 1933 to set in stone the fundamental law of securities: complete and accurate disclosure.

Today, interpretation of that securities law is dominated by court rulings from the 1970s and 1980s, including Basic v. Levinson Inc. (1988), which established the fraud-on-the-market theory. It asserts that investors count on the trustworthiness of the market as a whole, and in an efficient market, securities prices will rely on all publicly available information from a company. So if a company puts out misleading statements about itself, it will distort prices.

Since the mid-1990s, however, various rules and laws have tightened the circumstances under which plaintiffs can pursue securities fraud lawsuits.