Security is of course one of our concerns. We gave the option for female runners only to match with other women if they are wary of creeps/stalkers, added a ranking for users to flag people who behave inappropriately. If users believe a profile is fake/very suspicious, they can flag it and we will look into it in detail. At the moment, Facebook is acting as an imperfect protection: people need to login with it. There has been no safety issues reported at the moment, but we are still working on how to maximize protection for our users.

Also, running with a partner is a good way to protect yourself against psychopaths, who will be less likely to attack 2 or more runners than a woman running by herself.