First off, let me preface this with stating I don't know of any multis, nor do I have any.
Anyway, I was talking with some people that used to play CN, one of which is the infamous banned user Hurricane (he ended up moving to the same uni as I and we met irl), and we got on the subject of that one period of time the mods locked a bunch of nations (mine included) while they investigated whether we knew he had a ban evade. This made me think about whether it was a potentially bannable offense to know someone has a multi and not report it, but I cba to read the ToS to find out, so I'm asking here since a simple "yes" or "no" would be adequate.
Thanks.