The U.S. Attorney’s office in Massachusetts has charged Van T. Dinh, 19, of Pennsylvania, with identity theft. He is accused by the Securities and Exchange Commission hacking into someone else’s brokerage account to dump his Cisco Systems Inc. stock options.

According the SEC’s civil complaint, Dinh avoided a $37,000 loss on the Cisco options, which were trading below market value, by using someone else’s online account to sell them.

The SEC’s civil complaint alleges that Dinh invited users of an online investors’ chat room to check out a new stock-charting tool. The software tool was in fact a computer keystroking program called The Beast, which allowed Dinh to track the computer activity of anyone who downloaded it.

The SEC claims he used this ability to gain access to another person’s TD Waterhouse brokerage account and proceeded to unload the Cisco options.

The Journal reported that John Reed Stark, chief of the SEC's office of Internet enforcement, said Dinh “generated a market when there was none out there and set up an insurance policy for himself.” Stark recommended that Internet traders install firewalls and other security measures to keep their information private.