...
- (a) can use spam-forensics tidbits to great effect
- (b) is open source and therefore relies on public, open discourse
- (c) is in the antispam field, where secrecy can go a long way
I still haven't made any kind of hard-and-fast cut-and-dried decision. But my tendency is towards the following:
...
doh, I'd already written about this on the wiki – see also PublicRules.