For Augur, how it works is reporters are randomly handed events to report on. Meaning you can't buy REP and then choose to report on a specific event in order t

For Augur, how it works is reporters are randomly handed events to report on. Meaning you can't buy REP and then choose to report on a specific event in order to further your financial interest. Further even if you did that and by random chance are selected to report on your sporting event, you have to hope that majority of other reporters who were also chosen do the same thing you do (keeping in mind you don't know who they are), so if you still choose to report a lie you further risk losing a portion of the REP that you previously bought. The only practical way to game the system is to have a majority of all REP holders collude and they would in truth control the outcome of all events. However it would be a waste of their money to do so, because the value of REP is derived from trading fees, and their trading fees would be non-existent because no one would use Augur if the reporting wasn't reliable, so the value of their REP holdings would plummet. It's just like a 51% attack on Bitcoin, it's physically possible but you're financially incentivized against it.