I’ve just received confirmation from Strava Support that activities marked ”Followers only” contribute to the Global Heatmap. I think this is counter to what you would reasonably expect, and a potential privacy footgun.
For some activities (for example, those performed on my private property), I may want to allow my followers to view them, but not have them contribute to the Global Heatmap, because I don’t want to create trails that strangers might end up following. Currently, it does not appear that there’s any way to accomplish this, without opting out of the Global Heatmap entirely (which I don’t want to do — I love the Global Heatmap!)
Here’s the full statement from Strava regarding what does/doesn’t contribute to the Global Heatmap:
“Activities which use the 'Everyone' or 'Followers' privacy controls are eligible to be included in the global heatmap while activities which use the 'Only You' privacy control are not included. When it comes to the map visibility settings applied to an activity, portions of an activity hidden by an address saved to your account's Map Visibility settings will be excluded from the global heatmap while portions of an activity hidden by other map visibility settings will be included.”
I interpret this to mean that if I have an activity marked “Public” or “Followers Only” and but set the entire map to hidden, it will still contribute to the Global Heatmap — which I also see as problematic.
I think Strava should make the following two changes to enhance privacy of the Global Heatmap and bring it in line with reasonable expectations:
Activities marked “Followers only” should not contribute to the Global Heatmap, regardless of the map visibility settings on the activity.
Map portions hidden through any means (entire map hidden, start/end hidden, address hidden) should not contribute to the Global Heatmap.