I've gotten random DM invites in the past. I would ignore it or report it if you feel like they could be breaking site rules in some other way, as recording in itself isn't a rule, but it's not exactly easy to do since most platforms have live internal moderation, which would pull the stream (facebook, discord etc) down pretty quick. I agree with the person upthread, this could play a part. I think some people just want attention, no matter the form, and there are plenty of people here who may covertly be looking for those people who do want to stream it. Considering where these things end up (in the hands of gross people online) most of the time, I don't know how much I agree with the concept at this point, esp if its a method we have plenty of video documentation of (FSH, etc) — SN is an outlier here but we've only had one or two people actually have videos make it to the forum re SN.
edited to add: this is NOT encouraging anyone to livestream an sn attempt. but I have a mild understanding of why someone would. we mainly rely on written accounts to understand what fully happens to the body with this method, and some people really want or need a visual and it's not always for gross reasons. this isn't necessarily in support of this stuff whatsoever. just trying to see both sides.