This week, the Federal Trade Commission updated .Com Disclosures, the Agency's online advertising guidelines, acknowledging the vastly different online marketplace than the regulator confronted in 2000.

The general principles are the same--advertising must be truthful, not misleading, and adequately substantiated. But the facts have changed. In 2000, there was essentially no such thing as mobile shopping; social media meant insular, mostly static "boards"; and Internet Explorer reigned supreme. Today, American e-commerce is increasingly phone-based, social media is everywhere, and different browsers can offer very different viewing experiences.

All of which means that the regulated community has to speak to fragmented audiences through multiple channels, some of which can leave little room for error. A required disclosure can eat into Twitter's 140-character limit fairly quickly, for example.

Those affected by the new guidelines should assess their compliance across channels, particularly given that the document's release may set the stage for enforcement action. They are available here.