Let's say we're note-gathering at a conference about metadata formats for international science collaboration. Often we get remote participants who want to join the conversation, and selection bias says that they especially come from developing countries and can't afford to travel. Those constituencies may have vital information which will help to guide a standardization process for shared metadata.
If they are blocked, for whatever reason, they may be unable to contribute to the conversation. Maybe their missing voice means that metadata systems add another piece of systematic bias against them and further excludes them.
I don't know of any specific examples where this has happened, but the underpinnings are all true.
