Access to Feeds and feedsets is controlled by a Privacy Level setting. You can adjust the privacy level when you create a feed or feedset or by editing a feed or feedset that you publish.
Mark the feedset Private and you're the only user who can access it. Mark it Unlisted and you can give its DNS or BQuery address to other users but it will not appear in public listings. Mark it as Public and every other Karmasphere user can see and use it.