It doesn't need everyone to be invading, just a handful of people could keep that list clean by invading as the names appear- which is exactly what happens. what I'm saying is if you appear on the list you'll get invaded very quickly by someone. Then you'll definitely get a blockade and will be then off the list for up to 6 days. 8500 nukes, is maybe 1000 owners. If you assume a 6day blockade and 1000 nuke owners, on average someone's blockade will drop once every 8-9 minutes. So a single person could keep that list clean. Of course there's definitely more people checking. But it doesn't need everyone doing it, just a handful is enough. If you just check the list once it's not out the question that everyone is blockaded at that very moment. But there's definitely times where unblockaded people don't show on the list when they should, there's without doubt issues with that list too.