It's not that deep down... I answer quite a few question that are tagged with one low-traffic tag. Four or five people provide 90% of the answers with that tag

It's not that deep down... I answer quite a few question that are tagged with one low-traffic tag. Four or five people provide 90% of the answers with that tag (I've never counted exactly) and the same handful have done that for several years now. Would you be surprised if that handful of people got to know each other, in a semi-distant, pseudonymous way?