The Flag feature allows the Strava community to help keep segment leaderboards and segment data fair and safe. There are two types of flags:
1. Activity Flag: The activity flag can be found on any activity page, and can be used to flag another user's ride when there is evidence of GPS errors that lead to inaccurate segment times, or evidence that the data was driven in a car. If you have inaccurate segment times or data driven in a car, you can use the crop tool or contact support for more help.
NOTE: All flagged activities will be removed from leaderboards until the flag is resolved. Once an activity is flagged, a notification is sent to the owner of the activity, with instructions to resolve the flag or seek further help from Strava Support.
2. Segment Flag: This type of flag is only for segments, and should only be used when an existing segment is dangerous or provides some hazard or hazardous environment that should be shared with the Strava community. Flagged segments remove the entire segment leaderboard, removing all competition around rankings and segment times. For more information, see "Flagging a Segment as Hazardous".