This case was discussed on HN a few days ago, and from the comments there it seems there may be prior art from a 1997 MUD, which has been previously used to def

This case was discussed on HN a few days ago, and from the comments there it seems there may be prior art from a 1997 MUD, which has been previously used to defend against similar patents: https://news.ycombinator.com/item?id=16505568 https://news.ycombinator.com/item?id=16505568 Does the USPTO have any route for third parties to proactively invalidate patents or somehow trigger their reinspection other than during actual litigation? (Maybe an open group to prioritise patents and pursue this could get crowdfunding?)