Not allowed to record fancams in Japan?

I've seen some audience reactions though?

I could find a few but quality is awful

I believe they were quite strict about it, which is what we were told during NCT 127’s dome tour by J-Czennies. Some brave J-Czennie put her phone on record so all the other Czennies could at least hear the sound so 15,000 Czennies hopped onto a Twitter Space to hear this girl stream from her pocket while dodging security and some girls trying to dime her out through Twt.

In contrast all the other tour dates, people live-streamed the whole show or were quickly getting fancams up that night and into the next day.

Concert recording in Japan is really frowned up, if not outright banned for many shows

Partly for the enjoyment of others, partly brand/image protection

They are really really strict about recording and bringing cameras to concerts/shows in Japan.

Generally Japan is pretty strict about whether fam cams are allowed, usually they're not. I've seen some say this is due to tough copyright laws (only those that paid to enter should be allowed to view the concert, concerts may eventually be released on blu ray etc).

I suspect that it was a no filming policy and Japanese people are notoriously compliant about rules due to "don't bother others" mentality which is grilled into them from birth.