It was possible for users to have disproportionate influence on Digg, either by themselves or in teams. These users were sometimes motivated to promote or bury pages for political or financial reasons.
Serious attempts by users to game the site began in 2006.[29] A top user was banned after agreeing to promote a story for cash to an undercover Digg sting operation.[30] Another group of users openly formed a 'Bury Brigade' to remove "spam" articles about US politician Ron Paul; critics accused the group of attempting to stifle any mention of Ron Paul on Digg.[31]
Digg hired computer scientist Anton Kast to develop a diversity algorithm that would prevent special interest groups from dominating Digg. During a town hall meeting, Digg executives responded to criticism by removing some features that gave superusers extra weight, but declined to make "buries" transparent.[32]
However, later that year Google increased its page rank for Digg. Shortly, many 'pay for Diggs' startups were created to profit from the opportunity. According to TechCrunch, one top user charged $700 per story, with a $500 bonus if the story reached the front page.[33]
Digg Patriots was a conservative Yahoo! Groups mailing list, with an associated page on coRank, accused of coordinated, politically motivated behavior on Digg. Progressive blogger Ole Ole Olson wrote in August 2010 that Digg Patriots undertook a year-long effort of organized burying of seemingly liberal articles from Digg's Upcoming module. He also accused leading members of vexatiously reporting liberal users for banning (and those who seemed liberal), and creating "sleeper" accounts in the event of administrators banning their accounts. These and other actions would violate Digg's terms of usage.[34][35] Olson's post was immediately followed by the disbanding and closure of the DiggPatriots list, and an investigation into the matter by Digg.[36]
https://en.wikipedia.org/wiki/Digg#Organized_promotion_and_censorship_by_users
One big difference with SteemIt is that "Power Users" are by definition long term invested in the platform here, which is fantastic but may not be enough. It is quite normal for people to engage in short term thinking and undermine their own long term interests. Steem will need both long term and short term feedback loops, to encourage good behavior and punish bad. The limits on power should be accountability, and not just long term accountability.