Is someone who aids and abets a violation of Section 10(b) liable under the statute?

Charter Communications, Inc., a cable operator, engaged in a variety of fraudulent practices to pump up its financial statements so they would meet Wall Street expectations. When these efforts fell short, Charter approached two of its suppliers—Scientific-Atlanta and Motorola—for help in furthering the fraud. These two companies supplied Charter with the digital cable converter (set-top) boxes that Charter furnished its customers. Charter arranged to overpay the suppliers $20 for each set-top box it purchased, with the understanding that they would return the overpayment by purchasing advertising from Charter. These transactions had no economic purpose other than inflating Charter’s revenue and operating cash flow numbers by $17 million. They violated generally accepted accounting principles. The plan was successful— Charter did manage to fool its auditors.
The inflated numbers were included in financial statements filed with the SEC and reported to the public. Purchasers of Charter stock sued the two suppliers, alleging that they had violated Section 10(b) and Rule 10b-5. The District Court granted defendants’ motion to dismiss. The U.S. Court of Appeals for the Eighth Circuit affirmed. The Supreme Court granted certiorari.