<s>In my opinion, at least a few of his questions could be closed as off-topic if they aren't specifically asking something along the lines of "How can I change the configuration of my Captive Portal so that it can connect to iOS?".</s>

If his question is about doing stuff *on iOS* to make iOS devices work with a given WiFi captive portal, that sounds like it would better be asked on Ask Different or some other SE site. We've tended not to encourage iOS questions in the past (as discussed [here](https://meta.superuser.com/q/3266/144607) in 2011-2012), but it sounds like it may not be *technically* off-topic enough to put the question on hold.

This is really a gray area in my opinion. We have:

 - Lots of questions: some of which can probably be closed as duplicates of one another, but not *all* of them (for instance, some ask about documentation, etc.). Others can be closed because the site does not allow soliciting learning material, etc. But I'm sure there are at least 3 or 4 questions that are neither off-topic nor dupes.
 - A user who seems to behave in a fairly snarky way to the community (see [here](http://superuser.com/questions/941329/captive-portal-ios-osx-cna-popup-fails-to-login#comment1280531_941329)).
 - *Clear* evidence that no one in the active Super User community really seems to be able to provide the answer this guy is looking for. That's not to say there isn't an answer or that his question is bad (both of these things may or may not be true), but we don't seem to have the answer **here**.

I think the first step is to start whittling down the questions to a smaller, more manageable number:

 1. Put "On Hold" any questions that can justifiably be put on hold, as dupes or off-topic.
 1. Look into closing some more questions for other reasons, though those would be harder to justify (IMO).
 1. For the remaining questions, either leave them be, or drop a downvote if they just seem not to be a very good question.

I should mention that a sufficient combination of question closes and downvotes might question-ban this user, which would essentially solve "the problem" (the continued proliferation of questions) all by itself.