The Scot wrote:
Not only flag them but any time you see a runner you've not looked at before head to their profile and list of Strava pbs. If you see 12.30 for 5k or 3.20 mile follow the link to that run and flag that one too.
I do this! Whenever I get on a new leaderboard for a segment, I look at all the times that are faster than mine (men and women) and look at all of the associated activities. So many of them are clearly on a bike! Sustained pace of 3:15/mile? Nope... Flag, flag, flag.
I actually don't know what happens after I flag an activity. Of course, that person is instantly removed from the leaderboards for any segments from that activity -- but is the person notified and given an opportunity to just say "nope, I was running, I'm just really fast?" Or does someone from Strava vet it?