While religion has never occupied as much bandwidth on the internet as, say, saucy photos (what topic does?), it's been here for a long time.
The newsgroups system of the 1980s ("Usenet", "alt.", etc.) included several forums on religion: Christian, Jewish, Hindu, and atheistic.
At the time, the TCP/IP-based net hadn't been implemented much, and the average internet link may have consisted of two tin cans connected by a string, but those newsgroups circulated to most systems participating in the internet. Google's partial archive of just one newsgroup, "soc.religion.christian", has 41,000 discussion threads.
So, if you're under the impression that religious dialogue on the net happens within a "small community or closed channel", you're living a bit of a sheltered life.