We've all seen online banner ads with lengthy disclosures and other warnings that what we see isn't necessarily what we'll get. Think that the tight spaces of a smartphone screen or a 140-character tweet are exempt from the rules? Think again: the FTC just updated its guidelines to make clear that any "constrained" ads on mobile platforms or social networks still have to reveal their true purposes and show realistic figures. Marketers can't use multiple posts, pop-ups or other tricks to tuck the disclaimers away, either. The warning won't prevent your favorite celebrity from suddenly posting out of charac