I think that the idea of a "herem" [excommunication] is more of a serious  issue than most people are aware of. I was looking at the first chapter of Nedarim and I noticed there where the subject is brought.

The short and sweet of the subject is this. One under a  Nidui can learn Torah. But one under a "herem" can not learn nor teach. [That actual law is from Moed Katan]. So even if one would think the herem was based on a mistake it would not matter in terms of its validity.

So I try to avoid the religious world which seem to ignore the herem. And I can not figure out why the signature of the Gra seems to count for nothing for most people. [He who ignores a herem is under the same herem.]