Two California residents, Drew Moss and Sahar Maleksaeedi, have filed a class-action complaint against Twitter. The plaintiffs had previously opted-in to receive SMS messages from Twitter, however, when they opted-out, they claim all text messages from the social network should have stopped. Instead, they received one more message. They received Twitter’s opt-out confirmation message. The opt-out confirmation message practice follows the industry standards recommended in the Mobile Marketing Association’s Consumer Best Practices Guidelines, however, the two men allege that Twitter violated the Telephone Consumer Protection Act by sending an SMS confirmation to verify opt-out of future communications. This is the first time that a company has been sued over an opt-out confirmation message.