Spam stats

One technical interest I haven’t written much about here is spam. I have a fairly aggressive anti-spam setup, and I have a simple spam statistics page that gives hourly breakdowns. But what I’ve wanted for a long while is some way to aggregate spam stats from other servers into a sort of spam weather report. There are all sorts of reasons why this is impossible to do perfectly – people have different criteria for what constitutes spam, for one – but I still think a useful model for sharing data could be worked out. People who are already generating spam stats could publish their data in a microformat, for example. Alternatively, they could submit periodic automatic reports to a central server, which would then make the stats available in machine-readable form. The key would be to make it easy for people to make their data available.

This is sort of a lazyweb post. Does any project or standard for this already exist?