Dive summary: 

• Recently, Carnival Cruise posted nine clips of previously run 15-sec web ads on Instagram; the videos were removed shortly after for fear from the marketing department that they had violated Instagram's terms of service. 
• It is still unclear whether running ads that were shot outside of Instagram does in fact violate the terms of service, and Instagram declined to comment; in order to post the videos, Carnival had to use a workaround since the app requires you to take the video within the app. 
• If brands are finding ways to post pre-existing ads to Instagram through a workaround, or if the app changes its functionality, brands should be careful of overloading the site with too much and alienating followers. 

From the article: 

"Sometime after the ads were posted, the company's marketing department removed them, believing they may have violated of Instagram's terms of service, said a Carnival spokeswoman. It's not clear that Carnival did violate the terms and Instagram declined to comment on it. The videos weren't shot using Instagram and thus were missing the sepia-toned, artfully out-of-focus aesthetic that characterizes much of its photography."