Aerial heat maps released by firm Strava show all the activity tracked by users of its app which allows joggers to record their running routes.
"As bad as the publicly available heat map is, the underlying data that Strava is collecting is a security nightmare for governments around the world", Lewis said.
While in the US, Europe and other developed countries the heatmap lights up to illuminate a great deal of activity, in conflict zones it becomes nearly entirely dark. It also includes known Russian, Chinese and United Kingdom bases, but it would appear that it's more widely used by US personnel.
Prompted by the observations of 20-year-old Australian student Nathan Ruser, experts weighing in on Twitter have spotted what look to be USA and allied bases in Syria, French outposts in Niger, and Turkish troops on patrol in Syria.
"I wondered, does it show USA soldiers?" he said, and zoomed in on Syria. "It sort of lit up like a Christmas tree".
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He called it a grave and very painful situation, accusing the United States of working with terrorist organizations. The Kurdish-led administration of northeastern Syria appealed for a mass mobilisation in defence of Afrin.
Another journalist, Adam Rawnsley, noticed a lot of jogging activity on the beach near a suspected Central Intelligence Agency base in Mogadishu, Somalia, while a Twitter user said he had located a Patriot missile system site in Yemen.
The problem lies among a portion of the Strava user base.
Both the USA military and Strava say they are addressing the problem.
Chinese, Taiwanese, and other nations' bases were exposed too, but as the USA has the biggest global presence, it stands the most to lose.
There is a bit of blame on Strava here for publishing the information without thinking about the implications and repercussions it may have but once again, this data would not be there if it weren't for runners tracking this sensitive data. 13 trillion Global Positioning System points from their users (turning off data sharing is an option).
Strava has pointed out that the activities marked as private by users have not been included in the heatmap, and that activities have been cropped to respect user defined privacy zones.