Actually, this would be a fairly solvable problem: only show Vines from users with 400+ or more followers and older than a year (you may have to refine this metric to also examine the validness of their followers' accounts). Presumably, people with Twitter followings to care about won't just flash their junk...though maybe once in while, you'll get an Anthony Weiner.

In fact, you could probably get a certain class of videos by only showing Vines in which the tweets are directed at people, to catch the folks who forgot that @-mentions != DM (ala Anthony Weiner)

Defer the problem to Vine, surely?

They could hand curate the stuff that goes into the vinepeek pool.

Here we go: http://www.vineroulette.com - it allows you to search for any topic, or 'go random'. It combines all latest Vines in a full-screen visualization.

Edit: Discussion @ http://news.ycombinator.com/item?id=5124795