This draft attempts to establish a problem statement for "Captive Portals", in order to inform discussions of improving their operation. Note to Readers The issues list for this draft can be found at https://github.com/mnot/I-D/labels/capport-problem . The most recent (often, unpublished) draft is at https://mnot.github.io/I-D/capport-problem/ . Recent changes are listed at https://github.com/mnot/I-D/commits/gh- pages/capport-problem .