"Most social media are perfectly suitable methods for communicating with investors, but not if the access is restricted or if investors don't know that's where they need to turn to get the latest news, " said George Canellos, acting director of the SEC's division of enforcement, in a statement.

WSJ: SEC Says Companies Can Use Social Media to Alert Investors

"Steinberg essentially got an advance copy of Dell and Nvidia's quarterly earnings announcements, allowing him to trade on tomorrow's news today, " said George S. Canellos, acting director of the SEC's Division of Enforcement.

WSJ: SAC Capital portfolio manager arrested in NYC