There's more than one problem. Two at least. And the both of them are completely out of control.
Firstly the lists (printed or what, I don't know) circulating at the events. For me, it started with Brugge (about 20 fake logs), then came Mainz (minimum 60 so far). This will never stop - why should it? Once on the list, forever on the list. After the Giga is before the Mega, after the Mega is before the Tera ... Whoever tells me its my own responsibility to analyze the whole crap and delete it log by log didn't understand the dimension...
Secondly the lists and collections which are published at Facebook. Shortly after the last FB scandal about the published lists of Mystery cache solutions, there are new groups of cheaters who share every single TB code they ever found in the world. This is a real perversion of the idea of the game itself. Maybe of a 'side game', but of a part of our geocaching game, and it IS frustrating to face this without any assistance from the GS folks.
I've read a lot of very nice proposals here, really. Manual approval of logs, automatic preselection by distance rules, or at the least a possibility to lock (well, or archive) the own TBs... I'd appreciate ANY of these ideas to be implemented, to get rid of the mail flood. But how can you all bear (and sometimes apologize?) this inaction? Possibly, watched from Seattle, the problem is still too small and unconsiderable (what's 3000 TBs here in Germany...)? Sorry friends, this is about to grow and it WILL become yours.