The author spent a non-trivial amount of time researching the social media profiles and interactions in this group, and noted a pattern of interaction that was atypical between an adult and a minor.
If it was typical socialization within that community, then I find it unlikely he would have only found a single instance.
*edit to fix autocorrect typos
I think it is just sexual paranoia.
I mean here we are and someone somewhere happened upon a mailing list they didn't want to be on... looked folks up on facebook. Wrote a couple sentances on a blog and we're at "see something say something" and "The author spent a non-trivial amount of time researching the social media profiles and interactions in this group".
That all seems like a huge stretch that could create a situation where all sorts of normal behavior is scrutinized / fingers pointed, etc.
I find what is described as typical socialization observed by someone who knows nothing of these people as something to be concerned about to be fairly absurd.