The SEC has targeted the operators of dozens of fraudulent websites it says offer exorbitant returns on investments in a range of securities, including crypto assets. The SEC said in a lawsuit filed Thursday in U.S. District Court for the District of Massachusetts that the sites behind them promised returns as high as 61.9 percent within 24 hours. The defendants include the unnamed operators of sites such as GA-Investors.org (GAI), which guarantee daily returns between 2% and 4.5%.