Security leak in spf-* lists?

It may be a coincidence, but the day after I subscribed to spf-discuss (and
three related spf- lists) our domain started being forged by what looks like a
virus.

In the previous 6 months we've had about six '550' bounces returned to us. In
the four days of being on this list (and before I first posted to it) we've had
40.

Has anyone else experienced this 'coincidence'?

Chris Haynes