 With the exponential growth of the site's popularity over the course of 2006, upgrades were introduced leading to VideoSift 2.0 and later iterations that required new users to graduate through a "probationary period".This was meant to mitigate sockpuppet and astroturfing abuses that became more tempting for outsiders considering the site's increasing popularity.Routine administrative functions such as discarding expired videos are carried out by a bot named Siftbot.