Strava should give a way for participants to flag anomalies by other participants in monthly challenges.
For example, right now, the top 3 participants in the January 400 minute challenge, have activity times that are greater than if they continuously exercised for 24 hours every day non-stop. In fact the top guy has so far done 121,173 hours in 26 days - I don’t know if this is a Strava error, or ridiculous cheating. However, there is no way to flag this.