ine, Twitter's video sharing app for easily digestible 6-second clips, has been the toast of the internet since it launched last week. Creative-types love it. Someone even took the time to build a fansite, Vinepeek, that automatically streams newly uploaded videos in real time.

But the Vine love-fest isn't all hearts and puppy dogs — even though there is a lot of that. A modest search for the hashtags #porn or #sex reveals a vulgar depository of NSFW clips rivaling any curious teenager's browser cache. On Monday morning, Vine upset more than a few fans when it floated an explicit video of people having sex to the top of its "Editor's Picks":

OK, @vineapp showing a NSFW video on my at the top of my home feed as an 'Editor's Pick': not cool.

— Chris Hubbs (@cjhubbs) January 28, 2013

That #vine video I just saw when I logged in was pretty gross. It was NSFW and an "editor's pick". Someone was fired or hacked it I'm sure

— Savvy Mommy ® (@SavvyMommy) January 28, 2013

Not cool :/ RT @verge: Hardcore porn climbs to the top of Vine's 'Editor's Picks' vrge.co/112Anls

— Tom Warren (@tomwarren) January 28, 2013

Twitter has responded to the criticism, telling The Verge that users can flag spam or inappropriate videos to be taken down:

Users can report videos as inappropriate within the product if they believe the content to be sensitive or inappropriate (e.g. nudity, violence, or medical procedures). Videos that have been reported as inappropriate have a warning message that a viewer must click through before viewing the video.

Uploaded videos that are reported and determined to violate our guidelines will be removed from the site, and the user that posted the video may be terminated. [The Verge]

This particular goof-up has been fixed, but it still highlights a problem that app-makers continue to face as they amass audiences and scale quickly: Any company that leverages a pool of users to produce content will inevitably need to find a way to deal with trolls and troublemakers. Complicating matters is the fact that Apple, which explicitly bans NSFW content from its App Store, recently pulled 500px, a popular image-sharing app that also featured pornography.

Indeed, YouTube, Instagram, and other family-friendly services all faced similar NSFW hurdles at one point or another, but have since successfully instituted self-policing mechanisms to keep porn and other questionable content in check. Instagram, to its credit, does a fairly good job of taking down flagged content quickly and earnestly. With any luck, Vine will quickly learn from these experiences, too.