Among a number of other safeguards that I mentioned in a reply above, we often use well established and reputable data sources that either 1) already have restrictions on their employees trading on the event or 2) we enter into data licensing agreements with and require those restrictions to be put.
We also run KYC and pass all the participants through Politically Exposed Persons (PEPs) list, which allows us to flag people that are potentially close with a lot of our data sources (BLS, Nasa, MTA, etc.).
Our surveillance systems also do a great job of flagging weird activity (more in the post above) and anyone who we find to have done something wrong can be fined all the way to criminally prosecuted by the CFTC.
In short, a lot of similar safeguards to what you have against insider trading in stocks.