The Fabric experience is meant to be intimate but not invasive.
You know how many people in the app are nearby but you do not have their precise geolocation data. There is no longitude or latitude information available in the app. All data visible in the app is approximate, meant to point you in the general direction of others' posts.
Posting content is an invitation for engagement. If you are uncomfortable in a given context, you are free not to post and/or to remove your post.