Per https://ja.m.wikipedia.org/wiki/Wikipedia:%E4%BA%95%E6%88%B8%E7%AB%AF#.E3.83.A2.E3.83.90.E3.82.A4.E3.83.AB.E7.B7.A8.E9.9B.86 ja wiki users are running into blocks when editing on mobile phones. My Japanese is rough but it seems to stem from a 2007 policy banning all mobile phone edits due to poor quality content being added.
Version: unspecified
Severity: normal
Because we weren't sure if it was a policy or technical issue. We'll act accordingly depending on what we find and hear back from the ja community.
Looks like this is indeed a policy issue, and luckily it doesn't seem to be affecting the users who are editing via the mobile site (lots of registered editors are successfully saving edits from jawiki; as far as I can tell, the ban is targeted specifically at IPs). I sent a note to Philippe, asking if anybody in his community ambassadors team could poke into this and maybe ask the community to get the anti-mobile policy off the books.