http://www.five9.com/call-center-software/features/do-not-ca...
> Five9 helps you comply with this legislation by letting you upload your company's supplemental Do Not Call list, which prevents these numbers from being dialed by your outbound and autodialer campaigns, and even manual calls placed by agents. In addition, you can automatically track requests for Do Not Call from inbound return calls, and enable agents to fulfill callers' requests to be placed on the Do Not Call list in real-time.
It's easy stuff if you're trying to be legit. There are a lot of companies that don't make that effort.