I agree with DtR, if Strava is a pay service that "we pay" for and use for athletic tracking more tech monitoring must be built into the system. We use Strava for features to push hard. Some folks are not governing themselves so Strava is going to have to do it for them. Same day and approximate time rides should get bounced. I watch the same thing happen to myself, I get ahead and then a rider uploads his Garmin and his Strava tracked rides. I can see it in their feed. Double uploads around the same time and distance getting double credit. Fix it Strava!!! 

Hello @DtR & @janedoe9, 
Thanks for your posts. Duplicate activity efforts are not allowed on Strava segments and we do attempt to detect and block duplicate uploads if they have a similar start time. However, there are times that these are not detected. If you notice a duplicate effort, you can use our activity flag tool to report it. Find out more here

Additionally, we have an existing feature suggestion over on our Ideas Board related to this very topic. You can view it here, and we welcome your vote (hit the thumbs up button) and any comments you would like to add.

Thanks again for providing your feedback!